AFP card is dead... don't want to migrate to PCIE

Fastest AGP card is the GF7800GS.

If you go that route look for something like the Gainward one with is actually full 20 pipes not the crippled 16 pipes of most GS, thus making it near GF7800GT. Very best you can buy.

Now then for price/ performance, consider the X800XT, GF6800GS, X800GTO, and then the X1600Pro.

No the X1600Pro is nowhere near as fast as the X850XTPE, which is a great card, but usually much more expensive than the X800XT.

X1600Pro is only owrht considerin as a value for 1 game right now IMO, and that's Oblivion, for everything else, it sucks hard versus those other cards.

The regular GF7800GS is usually pretty expensinve ($250-300) and in it's crippled 16pipe format, performs in the same ballpark as the X850XTPE, but it does have a few more little options like SM3.0 support and FP16 blending (for enabling some additional versions of HDR [OpenEXR]).

Just a few things to consider.

PS: Something else to consider, sometime it makes more sense to upgrade the MoBo and buy a PCIe card since the AGP cards are often found for a $50-100 premium, it just depends alot on your CPU. If you've got an AthloonXP (not AMD64) then you're hooped, everything else there's usually a cheap upgrade path worth considering. Especially if a GF7800 GT is $60 cheaper than a crippled GS, then the difference in money gets you a full GT and a nice new MoBo that will take you further. But if you're set on migrating this hardware to your son, then consider the first things I wrote.