😉 Yep the Rad8500 are better than the GF3 cards so long as you don't mind compromising AA and high quality Aniso for the hugely better image quality, TVout, dual display and hw DVD playback. With a fast CPU you really shouldn't skimp out as the GF3 and Rad8500 cards tend to gain very little after Athlon1.4ghz, GF4TI cards continue to boost perf with every mhz your CPU can throw at them! Another benefit is that GF4TI cards are much better all-rounders than GF3 or Rad8500 as they offer great 3D perf, image quality, AA, Aniso, dual display, make better use of faster CPUs and have better TVout than GF3s. If you go Radeon be sure to double check as features and clock speeds vary from manu to manu as well as oem vs retail, still generally preferable to a GF3 though.
🙂 Whatever card you get I'd strongly advise 128MB, Rad8500LE-128MB is better than Rad8500-64MB and the same for GF3TI200-128 vs GF3TI500-64 (unless you are terrified of o/c'ing). On a fast CPU it would be worth considering a GF4TI4200-64MB over a 128MB GF3 or Rad8500, these tend to reach GF4TI4600 speeds, the 64MB will be hit hard but on a fast CPU like yours you'll still be a fair bit faster. See what the prices are like and weigh up your reqs but I'd strongly urge you to consider paying a little more for a 4200, esp the 128MB version otherwise Rad8500 is generally the better choice than GF3.