Its gonna be expensive if you plan to go PCI-E. You need to replace almost everything.
If you can hold off for a bit, PowerCooler is actually making a decent $250 (msrp - so expect to buy it for less) vid card that is actually decent for AGP:
http://www.powercolor.com/global/mai...ail.asp?id=137
The best part is, it already has an Arctic Cooler onboard!!!



I had to buy an Arctic Cooler seperately for mine and install it.
-S