@Roman78: i had the same dilemma back a month ago
I restored a very old Amiga 600, just to play games. Even tough i know 1200 have better graphics and 020 and all that, i just wanted to have a small machine, with a "big hardisk" inside, with plenty of old games (non aga, of course)
I was visiting Greg Donner excellent site (Wokbench nostalgia), and found about people complaining that they couldnt use larger hdd with Kickstart 37.300
Let me tell you, i have done it with no problems!!
I have a 2 GB disk (4 partitions), FULL of WHDLOAD games, and i installed Workbench 2.1 with no problems!!
If you need more advice, just PM and i will tell you how to achieve this!!
Its lovely to put your 600 in a bag, and go to a friends house, for a saturday night, peanuts, lot of beer, and a truly retro-gaming experience...
:-D
Cheers!
Sebastian