New server(s)

We are getting Hughes net Friday and I can't get either of my desktops to work.  They are quite dated at this point anyway but still have some good spare parts.  I want to build a new server or possibly two.

Things that will influence the build:
-Since it is Hughes net, there are restrictions on amount of data transferred
-To reduce ram usage on the server, run level 3
- Probably want i7 core with 12-16G ram
- I think I have hard drives large Enuf already
- will need two nics to setup as firewall
- I am limitted on space somewhat so I may not be able to setup 3 or 4 servers but I wud kinda like to.
- Also plan on using vonage so I need to make sure it can be configured for proxy

Network services server:
The services I had in mind are: dhcp, DNS, ldap,  firewall, proxy, package report, bandwidth monitoring, web service, log server, and anything else needed.
I was thinking of running Centos 6 but I wud like to use lmde since that is what my laptop and netbook run.  It is just not ootb to setup lmde with lvm.
Also considered clearos but from the floss weekly episode it sounded like it was all run level 5.
If I had more room I might do a cheaper build for just a clearos server and have a separate internal network services server.

Other server possibilities:
I'd like to have a NAS box of some sort as well with maybe a raid controller (for speed).  Or just some large and fast disks in a redundant raid for some reliability.
I'd also like to setup a pvr machine.  Maybe use mythbuntu and set it up for ripping DVDs to stream to other devices.  Great for movies in bed on a laptop.  Cud even get a TV and put a small PC with it that cud stream.  The main pvr cud have a volume on the NAS.

Also need to know if there is a good way of handling Xbox traffic.  Does a 360 support proxy?