You wouldn't want a Rad9000, they are worse than the Rad8500LE, even though 8500 cards are cheaper. It is simply cheaper for ATI to manu the Rad9000. After all ATI only need the card to trounce the nasty and misleading GF4MX cards and not the superior GF3. Expect Rad8500 production to cease shortly.
I don't think you have to be too concerned about the $10 difference so both cards break down like this.
Regarding drivers, nVidia are well known for excellent (and truthful) drivers, but I believe ATI are just as good now. But beware, once again you can be caught out if you buy 'powered by ATI' rather than 'built by ATI', some non-ATI Radeons don't work with the standard ATI drivers, NOT a good situation to be in, esp long term.
Pure perf, the Rad8500 beats the GF3TI200 (even when GF3TI200 is o/c'ed), although the difference isn't huge and does vary depending upon the game. AA perf the GF3 is streets ahead, the Radeon8500's AA is nice and sharp but it kills perf. Much better off with a GF3 using either 2xAA or QxAA & Aniso, greta perf and good quality. When it comes to '2D' image quality and TVout the Radeon cards are FAR superior. Aniso is a mixed bag, Radeon is faster but the GF is much prettier, so that evens out. Both cards do all necessary DX8 hw funcs so that doesn't help to decide between them either. IT IS TOO CLOSE TO CALL, if your bro cares about street cred, the GF3 will prob be better suited, and is a tad cheaper too.
A final point, get a 128MB card if you can. Not only does it appear to be a lot more expensive and have better 'street cred', but it will become more and more important over the coming months. A Rad8500LE 128MB is a much wiser purchase than a Rad8500 64MB, likewise it is worth paying a bit extra for a GF3TI200 128MB over a 64MB version. See how much extra a 128MB card will cost. AVOID non-ATI Radeons, and pref get retail rather than oem versions as you get a much better card with better support and faster clocks. For GF3 brand truly matters little, but again retail is a nicer choice if it's intended as a gift.