I would go 64-bit for a web server. If you have the money for state of the art get one of these 64-bit Alpha's, IBM's, SUN SPARC's. True internet speed max bandwith. Or if its a plain old site a Celeron 733, 128mb sdram, i810e MATX w/ onboard video, 10gb in WIN ME would be a good speed. If its a very big site Dual P3 700, Serverworks Motherboard w/ RAGE XL 8mb, 256mb sdram, 40gb, WIN 2k could do it just fine. Ultra huge site then Dual P3 XEON 700 L2 2mb, Serverworks mobo w/ RAGE xl 8mb, 512mb SDRAM, 100gb, Win2k Server should do well.
Note: AMD processors are okay(fast and nice) but your Server is on 24/7 and really busy at times. So the p3 runs cooler then the Athlon or Duron so the only real choice is a slower p3 processor.
Leader of the Anti VIA-Nvidia Army