1st of all...DON'T TYPE IN CAPS! It's rude & is considered to be SHOUTING!
Hopefully he has an AGP slot...if he's limited to PCI, he really only have 2 choices. FX5200 or FX5500. You may be able to find an FX5700LE in the PCI format, but they're becoming hard to find & they're expensive. But if he has an AGP slot, he has plenty of choices:
In the ATI line, the card will have to have a numerical number of 9500 or higher. In the nVidia line, it would have to be an FX5200 or higher. Beware cards that use 64-bit memory, they're at least 30-40% slower than their 128-bit "bothers".
If you want good but cheap, get a Radeon 9550 128mb/128-bit card ($60):
http://www.newegg.com/Product/Product.asp?Item=N82E16814121511
I have the above card myself & am very happy with it. I used ATiTool to overclock it to 9600 speed with no probs. There are a couple other 9550s at newegg that are a little cheaper, but Asus is a reputable brand...plus this card has a cooling fan, the others don't.
If you're willing to sacrafice performance for a lower price, have a look at this FX5200 128MB/128-bit card ($42):
http://www.newegg.com/Product/Product.asp?Item=N82E16814133144
But if you're willing to spend a little more & get a better performing card, step up to the Radeon 9600XT ($83):
http://www.newegg.com/Product/Product.asp?Item=N82E16814125124
ASUS A7N8X-X
Athlon XP 1800+
8.5 x 200MHz
1024MB PC3200 2.5-3-3-7
Asus A9550GE/TD 128MB
WinME/WinXP Pro SP1