Or you can go for OS 3.5 og 3.9, Amigakit supplies them with a emergency boot disk now, so you dont need to have a working 3.1 installed first.
But then you need to connect a cdrom, and get more memory (did i mention that I try to get rid of a 4mb+rtc card for a1200?

), and then you'll find out you need a decent accelerator and graphics card,
and then you want to get networked, and that cheap amiga suddenly turns expencive, hehe. but hey, thats what we all end up doing when we return to amiga...