It depends partly on where you live.
If you live in the UK there are a number of wargame shows where there are "bring and buy" sales of all sorts of second hand painted figures. There are also several people who trade in second hand miniatures.
An alternative (although normally more expensive is EBay)
To start with it is alwasy possible to play the game with just blank bases, this is heresy for some wargamers ut as a way to get started it is fine.
Another way to get cheap (unpainted) miniatures would be to look at the plastic figures from the likes of Hat and Zvezda. There is a super resource on plastic figures at
www.plasticsoldierreview.com
Getting the rules would require you to be enrolled in the beta program and normally entry to the program would require you to have a playing partner as it is difficult to test the rules if you aren't playing.
There will be Irish armies in the AoW lists. They will have a lot of undisciplined infantry in almost every era. Over time the precise composition will vary widely so it is difficult to be too precise.
