Chaintech 6600GT + BioStar NF4UL-A9

My first purchased part towards a new Athlon64 system is a
Biostar NF4UL-A9 mainboard. This board has PCI-E, and AGP support. The
XGP (Xtreme Graphics Port) lets you use AGP vieocards, but only a
limited amount of them. There is a short list of them that was tested
by Biostar to work properly on their site. No Nvidia 6xxx cards are
listed, but I've read elsewhere that people have used 6xxx AGP cards
just fine, but none listed a Chaintech model. Anyone have this
mainboard, and a Chaintech 6xxx AGP card running on it?
I know I should purchase a PCI-E card, but I can't afford to
drop $300 towards a 6800GT (which would be the logical next step),
since I'm already spending $300 just for the mainboard, and Athlon64
3200+. I'm hoping my 6600GT AGP can hold me over till I can afford a
better PCI-E card.