If I was you, I would prefer an OS3.1 installation + tweaks. OS3.9 can be really nice, but I think it's much slower on a system with your specs. I've heard some good things about
AmigaSys AGA. Why not try that, in combination with OS3.1? You can install it under winuae, and if you like it, copy the whole configuration to your CF for use in your real A1200.
