Hardware:
Asus P4P800 Deluxe - all the usual stuff, onboard sound, usb, etc
Pentium 4 1.6a at 2.1Ghz
1.5GB of RAM until one of the other boxes needs some
Seagate 80GB IDE harddrive
Random, Unknown CDRW (untested so far)
GeForce 2 MX400 (Tier 2)
Sony 27" Trinitron (NTSC-M)
Haupauge 350 w/ remote (remote is tier 2)
Microsoft Sidewinder USB gamepad
Generic keyboard
Extremely faulty MS 5-button mouse
Everything on the list acted exactly as expected (or better) except the graphics card and remote. I did do a set of modprobes on the gamepad before starting xmame, but not sure ifthey were necessary.
Gamepad worked perfectly with ZSNES and MAME frontend configuration screens, Haven't tried any of the other emulators.
Using an NTSC-M signal over composite.
For the record, this was just a test. Real hardware for the box is in the works. For more info on the GeForce 2 issues, check tier 2 posts.