Try an Emulator and see if you still fancy playing after a few weeks. If you do get a real A1200 (£30 on fleabay), a turbo card (min 030/50) some ram, and maybe a compact flash harddrive (just a little adapter for a few quid", and a compact flash PCMCIA adaptor (£3?)
You can install hundreds of games and demo's using a program called WHDload. and use the PCMCIA CF to transfer data from the PC. WHD also allows you to install lots of old A500 stuff that was not compatable with the A1200, and can now also be HD installed.
Get a copy of eagleplayer/delitracker for old mods, and modern
PC ones as well.
MODS and Demo scene stuff are still being produced today.
Get a nice telly, munchies and beer, and your away!
Oh, and don't forget your scart cable! I use my A1200 so I can use the big TV in the lounge, I don't want to be sat in front of a monitor.