Recommend Generic Smallish PC for Linux Play

Been out of the PC hardware main stream for a bit now. Could someone recommend a reputable company that sells a smallish "generic" pre-assembled PC towers or desktops? I'm just looking for a cheap platform to mess with Linux builds on. No gaming, maybe some limited DVR and video/media out to TV, definitely some VM hosting and file sharing duties. I'd like to find something that will support 8GB of RAM, a RAID card at some future point and a decent dual core 64 bit CPU. Anyone have a vendor they recommend? Probably will be playing with openSUSE, various BSD variants and some openSolaris. Budget is between $300 to $400 and I already have keyboard, display, etc... I'm not really in the mood to scratch around the internet for parts, so I'm hoping a assembled, or partially assembled system might be out there somewhere.
Thanks!

Hp is pretty good, dell, lenvo, acer and asus at that price range I would suggest looking at the net top pcs or maybe hit up tigerdirect for the barebones kits

I would check out tigerdirect for something like that.

I was just on Tiger and they seem to have some options that would work. I think I'll call tomorrow and see what they can build. My also check the local "PC Hut" type places and see what's discounted on the shelves. Thanks all!

EDIT: "just on Tiger" - that didn't come out quite right.