LinuxQuestions.org - Web Server Hardware Recommendations

Hi,

For the past week or so I've been looking at building a small rackmount server to be colocated. I would prefer to keep the price around 1000 dollars Canadian (approx 748 USD).

Server's user base:
Some 25 users who currently use Yahoo! Groups for collaboration.

Server Usage:
-group website, with calendar, mailing list archive, member directory, polls, member provided content etc.
-individual websites for group members
-mail server for group members
-mailing list (peak usage is about 220 messages/month)
-development test server for ASP.NET app's using mono

So the server will likely be running a web, database and email server as well as the usual assortment of things (ssh access, probably secure ftp etc.)

I'd like to limit the server size to 1U, at most 2U.

Currently I'm looking at the following hardware configuration:

- Pentium 4 2.4Ghz, 533MHz FSB
- 512 MB DDR RAM
- Samsung 80GB ATA100 7200RPM with 2MB Cache
- Intel P4 478 Mainboard
- Integrated 10/100 NIC
- 1U 200watt P4 Power supply

How does this sound? Too much power? Not enough? A few things I've generally seen in database/web servers that I haven't done here:
-dual cpu - would it be better to try to find a lower speed (pentium III 500?) and have two (and compataible mainboard)
- RAID harddrive configuration. I'm pretty much limited to RAID 0 or RAID 1 in a 1U case as generally there is only space for 2 harddrives.

And finally any software recommendations?
-I've used both Mailman and QMail before. Qmail seems to have very sparse documentation. Recently I've found James on the Apache project which looks interesting as it will allow me to develop my own mail list rules fairly easily.
-As far as distributions, I'm thinking of either RedHat or Crux.

Thanks,

Joe