Almost $1000 for a motherboard with out dated GFX, and SLOOOWWWW 800Mhz CPU.
I really dont think that 800MHz is *that* slow. You've got to remember that you aren't actually running WindowsXP on it.

The problem you are facing is that to upgrade your a1200 is going to cost you a lot of money unless you buy one ready made. I suggest you check out
www.amibench.net everyday for a few bargains.