I'm not qualified to answer your question, so take this with a grain of salt (if nothing else this will serve as a starting point for discussion)....
How much oomph you need will depend on how many zones you plan on hosting and the # of losers (errr... users) you plan on hosting.
My best guesstimate is that you'll want 256MB of RAM and a 500MHz P3. You can always start with 128MB of RAM and another stick if you start seeing swap space being used. You shouldn't need much disk space at all (~5GB drive will suffice). For a dedicated server you wont need to install X (if you want X, then throw in a 10GB drive to be safe).
You better have a cable modem or DSL with at least 128kbps uploading speed. A 256k (or more) upstream connection would be preferred.
I'm using a 700MHz Celeron with 192MB of RAM, but I will only be hosting 4-5 players and 2-3 zone servers at most. My machine runs low on RAM (i.e. uses swap) because I'm also running a forum on my server with ~70 users and 2000+ posts (mysql eating up memory).
==Flipper==
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