Hardware Recommendations for a School Server?

nychef asks: "My school has decided to give me money to set up a server for my club. I'll be running e-mail for about 250 people, and webpages for about 100 which will mostly be static webpages, but there will be a few dynamic ones. I am trying to figure out just how powerful I need the hardware to be. They gave me a pretty decent budget, but my budget is to include the internet line. So I want to maximize bandwidth and minimize the cost of the server. I am looking in the range of dual P4 2.8's with a 3 disk RAID5 stack and 1 GB of ram. Is this adequate or overkill?" nychef has a budget of about $4,000. What kind of hardware and bandwidth options do you think he can afford?