Thanks for the explanation and comparison uran21, funny how the lists overlap so much. One thing I thought was interesting is you mentioned reconnaissance planes... Nobody else commented on it, but when I just reread this thread after a few (busy) days, I have a few questions and remarks about them, since when I made my 'wish' list I didn't assume any new unit classes were going to be considered. That's why I wasn't sure about the amfibious tanks, and you confirmed my suspicions with the same reasons, that is they would be troublesome from a gaming perspective.
Since you mentioned you want to see if recon planes can be added, another big story, I hope you won't mind.
About the recon plane you proposed, the Avro Anson, that one has me a bit puzzled to be honest. It's only reconnaissance role was that of an ocean patrol bomber, like the
Consolidated PBY 'Catalina' flying boat or the German
Focke-Wulf Fw 200 'Kondor', flying over the ocean to spot ships. It was quickly superseded by the
Lockheed Huson and
Ventura I believe?
But anyway, this sort of recon is more of a strategic role, which will be hard to translate to this type of tactical game I think. Over land, similar planes (F-10 (B-25) Mitchell, Lockheed Hudson/Ventura) were used for photo-reconnaissance, but usually these bigger and slower aircraft were used only for mapping purposes over relatively safe areas. Photographing enemy units/installations required flying fast and/or high, these missions were either flown by single-engined fighter planes or light bombers (both types converted to this role). See for such organizations:
http://en.wikipedia.org/wiki/5th_Photog ... e_Squadron
http://en.wikipedia.org/wiki/1_Photogra ... sance_Unit
The most used planes for photographing enemy units/installations by the western Allies were:
UK: Spitfire and Mosquito (both had 'PR' versions)
see
http://airrecce.co.uk/WW2/recce_ac/RAFAR.html and
http://airrecce.co.uk/WW2/recce_ac/RAFARP2.html
USA: P-38 Lightning (called F-4,later
F-5 version), later on the P-51 Mustang (called
F-6).
A lot of info about WW2 equipment used for photo recon can be found here:
http://airrecce.co.uk/WW2/ww2_index.html
But there are other types of reconnaissance, and the way spotting and recon in the game works now I assumed any recon planes would have the purpose of 'tactical reconnaissance' or 'battlefield reconnaissance' or be used as 'observation/spotter planes'. The Germans had different names for each category. The western Allies had more overlap in the roles and used terms as 'observers', 'army cooperation', Air Observation Post (AOP), 'Rovers' or 'forward air control' (FAC), the distinction between all these concepts is blurry at best, but I'll give a few examples:
Tactical recon, a mixture of low-level photo recon and direct observation, missions could be planned or by request of higher ranking command units to get a better picture

of what is happening. A few examples of western Allied units flying more diverse tactical reconnaissance missions (army support):
http://en.wikipedia.org/wiki/10th_Tacti ... rld_War_II
http://en.wikipedia.org/wiki/No._208_Sq ... rld_War_II
http://en.wikipedia.org/wiki/No._6_Squa ... -war_Years
Than there is battlefield recon or FAC, which is low-level loitering, direct observation and often close cooperation with front-line units.
So basically, if we simplify it there are three types of recon. First, big, slow aircraft flying high to photograph landscapes for mapping purposes or doing long patrols (mostly over water) to spot enemy activity. Secondly, the strategic and tactical pre-planned recon (mostly photo) missions for regonial (or high) command and thirdly, various forms of battlefield recon immediately preceding and during operations to aid local ground commanders. There is overlap but I use a simplistic distinction: if a mission cannot provide real-time data and is pre-planned, it's not a battlefield recon mission.
The pre-planned photo mission is simple: the plane flies over an area and takes photos, flies back to base. The film is unloaded, developed and examined. All this takes time and info can get outdated rather quickly. So mostly useful for planning operations by assessing enemy placement, strength and force composition. Also used to recon targets for bombing and assessing the damage afterwards. They generally did not use radio in order to prevent detection, so could not provide real-time data, and did not directly cooperate with other units other than their escorts, they had a mission of their own.
Battlefield reconnaissance: (the name is more of a German name, and overlaps with the Allied concept of FAC) This role uses a small or specialized recon plane with observers and radio to report on anything they see, or stay in direct contact with artillery or fighter-bombers to direct their strikes. They also frequently operate from front-line airfields and are used on request by local commanders to scout and look for anything. A famous WW2 example of 'Battlefield recon' is the Fw 189 Uhu, while the Allied form of FAC is more typically represented by the American Stinson L-5.
So roughly there are several types of recon plane:
(Ocean) patrol and mapping: Big heavy planes, mostly older bombers.
Photo recon: mostly modified fighter planes or fast (fighter-)bombers, missions could be
low-level and
tactical in nature, but are almost always pre-planned. Aircraft sometimes (partly) retained armament.
Battlefield recon or FAC: Light aircraft that specialize in low-level loitering and observe mostly directly, and use radio to closely cooperate with ground forces (recon/liaison), artillery or fighter-bombers (observing/spotting).
USA:
Stinson L-1 'Vigilant',
Piper L-4 'Grasshopper',
Stinson L-5 'Sentinel'
UK:
Taylorcraft Auster,
Westland Lysander
Germany:
Hs 126 Fi 156 'Storch',
Fw 189 'Uhu'
So aerial recon can be modeled very differently depending on how you wish to use the concept. Some ideas of mine:
For patrolling and mapping, (obsolete) bombers like the Avro Anson could be used, with very limited offensive/defensive capabilities, or specialized only in anti-naval attacks. These are basically two categories, one is an anti-naval patrol medium-heavy bomber that can spot along the way, and the other (photomapping) is a light bomber with a large spotting radius. Both would have reasonable cost but be very vulnerable. The anti-naval patrol bomber would be in the tactical bomber class in PzC so it can attack submarines and will be less effective and more vulnerable when attacking naval targets.
For classic tactical photo missions, all icons are already in the game, it basically becomes an unarmed tactical bomber (PzC class) based on a fighter, so that it can be escorted. Units would be relatively expensive but fast, with more fuel than their 'donor' plane. Units would not be able to spot along the way, but with large spotting area as per uran21's proposal.
For FAC, new icons would be necessary, but they would operate as very slow and vulnerable tactical bombers (PzC class) without attack/defense capability, and very cheap. Can spot along the way, but with reduced spotting as uran21's proposal. Their slow speed would keep players from quickly revealing large sections of the map. It might be interesting to have it give a sort of bonus to friendly ground units inside it's spotting range, maybe +1 initiative (or +1 attack for artillery), like with the radar structure, or a negative bonus to enemy units in it's spotting range. This might motivate players to use them close to the front-line instead of zooming around around the map with two fighters permanently glued to it.