Have you considered NAS (Network Attached Storage) "appliances" at all?
Most people who say "I need a server" don't really *need* a full, complicated, hard to setup and manage server.
With NAS you get a platform-agnostic (Win/Mac/*NIX) beefy hard drive available on the network that is managed (usually) through a web-based interface. If you don't need a firewall, mail server, web server, print server, Active/Open Directory user account or already have that you might go with NAS.
And you may want to talk to a consultant. They cost more but you usually have someone local to deal with selecting and buying hardware, setting it up and even supporting it for you.