There are very few 6600 GT's for AGP bus, but there soon will be. Wait another couple few months before buying your card and there should me many more from which to choose (the prices will also get nicer). I've also heard tell that ATI won't be coming out with their competitor to the 6600 untill q2, 2005, so they plan to reduce the price of their 9800pro series cards. This may be a better option depending on what your preferance is.
J