Need advice on a new midrange.com server config

[David Gibbs <david@xxxxxxxxxxxx>]

Folks:

I've placed an order for a new machine to run midrange.com.

It's a Dell Poweredge T310 ... it will have 8gb memory, Intel X3450 Xeon Processor (2.66 GHz8M Cache, Turbo, HT) & 500gb RAID 1 disk (2x).

Currently I run midrange on a pair of Poweredge servers, both running Fedora 10 ...

Rivendell runs the mail server (including anti virus and anti spam), list server, mysql, java based chat server, and is a general file server.

Gondor runs the list archives, search engine, and blogs.

I'm mulling over how I should configure the new system.

Do I migrate everything to the new machine as a single Linux install or should I consider re-implementing both systems as individual VM's on the new machine?

Regardless of how I reconfigure, I'll probably be switching to Centos for the Linux distro.

Any suggestions?

A few things to think about: 

1. Which free VM implementation should I use?  I've used VMWare server in the past, I currently use virtualbox, I can also consider looking at XEN.

2. Should I enable hyper-threading on the processor?  Is it advisable if I use VM's?  My database processing tends to not be intensive.

Thanks!

david