Most games run on your setup.
A500 (with a little more memory) is perfect for running most games.
That is you should at least upgrade your rom to 2.04 or even better 3.1(vesalia.de or amigakit.com).
And you should get your hands on a A590 or similar which off course can be expensive.
You could go for the 1200 which you should buy with harddisk otherwise it will not be easy to find yourself a small and reliable harddisk which will work correctly with te 1200(size not bigger then 4GB and powerconsuption not to high and must spin up fast so you should,t reboot at cold start).
