That order of battle is too comprehensive in that it includes units from Anzio, the Adriatic coast, and northern Italy. I am culling it down, based on this map from Atkinson's book:

- Operation Diadem 2.jpg (232.78 KiB) Viewed 1661 times
I did not use it as the template (I found another highly detailed map for that purpose) but it is very useful for listing the units actually in Operation Diadem. For that reason, I am leaving out the British X Corps (which included the friendly Italians, NZ and SA troops that you mentioned, Colonel, so there is no reason for them now) in that even though X Corps is on the map, it was too far north along the Gustav Line to be part of the action that I am showing.
So here is the selected OOB for
Operation Diadem; it may seem a bit one-sided in favor of the Allies, but bunkers and foxholes can do wonders for evening up the odds!
ALLIED
British XIII Corps
Lieutenant-General Sidney C. Kirkman
British 4th Infantry Division (Major-General Dudley Ward)
British 6th Armoured Division (Major-General Vyvyan Evelegh)
8th Indian Infantry Division (Major-General Dudley Russell)
British 78th Infantry Division (Major-General Charles Keightley)
1st Canadian Armoured Brigade (Brigadier W. C. Murphy)
I Canadian Corps
Lieutenant-General E. L. M. Burns
1st Canadian Infantry Division (Major-General Chris Vokes)
5th Canadian Armoured Division (Major-General Bert Hoffmeister)
British 25th Army Tank Brigade (Brigadier J.N. Tetley)
Polish II Corps
Lieutenant-General Wladyslaw Anders
Polish 3rd Carpathian Rifle Division (Major-General Boleslaw Bronislaw Duch)
Polish 5th Kresowa Infantry Division (Major-General Nikodem Sulik)
Polish 2nd Armoured Brigade (Brigadier-General Bronislaw Rakowski)
Corps Expéditionnaire Français (French Expeditionary Corps) (on the Winter Line)
Général d'armée (General) Alphonse Juin
3ème Division d'Infanterie Algérienne (3rd Algerian Infantry Division) (Général de division (Major-General) Joseph de Goislard de Monsabert)
4ème Division Marocaine de Montagne (4th Moroccan Mountain Division) (Général de division (Major-General) François Sevez)
2ème Division d'Infanterie Marocaine (2nd Moroccan Infantry Division) (Général de division(Major-General) André W. Dody)
1ère Division Française Libre/1ère Division Motorisée d'Infanterie (1st Motorised Infantry Division) (Général de division (Major-General) Diego Brosset)
Commandement des Goums Marocains (Command of Moroccan Goumiers - Three Groups of Tabors each comprising three tabors of 500 to 800 men) (Général de brigade Augustin Guillaume)
Corps Troops
7ème et 8ème Régiments de Chasseurs d'Afrique (7th and 8th African Light Cavalry Regiment)
Régiment d'Artillerie Coloniale du Levant (Levant Colonial Artillery Regiment)
64ème Régiment d'Artillerie d'Afrique (64th African Artillery Regiment)
Groupe de canonniers-marins (Navy Artillery Battalion - two batteries)
U.S. II Corps (on the Winter Line)
Major-General Geoffrey Keyes
U.S. 88th Infantry Division (Major General John E. Sloan
U.S. 85th Infantry Division (Major General John B. Coulter)
1st U.S. Armored Group (three tank battalions)
GERMAN
Tenth Army (on the Winter Line)
Commander: General Heinrich von Vietinghoff
XIV Panzer Corps
Lieutenant-General Frido von Senger und Etterlin
15th Panzergrenadier Division (Major-General Rudolf Sperl)
71st Infantry Division (Major-General Wilhelm Raapke)
94th Infantry Division (Major-General Bernhard Steinmetz)
LI Mountain Corps
Lieutenant-General Valentin Feurstein
1st Parachute Division (Lieutenant-General Richard Heidrich)
5th Mountain Division (Major-General Max-Günther Schrank)
44th Infantry Division (Major-General Bruno Ortner)
114th Jäger Division (Major-General Hans Boelsen)
Army Group Reserve
1st Paratroop Panzer Division (Brigadier-General Wilhelm Schmalz)
26th Panzer Division (Lieutenant-General Smilo Freiherr von Lüttwitz)
29th Panzergrenadier Division (Lieutenant-General Walter Fries)
90th Panzergrenadier Division (Major-General Ernst-Günther Baade)