OK, I got the whole shebang set up, P-III/800, 256 MB, 30 G HD, GeForce2 MX400 and Mandrake 8.1. It looks like a keeper. A few points:
1) Use of the supplied heatsink and fan seems to be the only way to fit a GeForce2. Most other heatsinks and fans are too tall.
2) The supplied fan is too noisy (need to find either a replacement low-profile fan/heatsink, or at least a fan that mounts on the supplied heatsink).
3) Depending on the height of the DIMMs, there can be mechanical interference with the PCI card. I have a standard full-height DIMM that clears the GeForce2 card by less than 1 mm.
4) The GeForce2 (Visiontek Xtasy) is auto-detected and the onboard video gets disabled without any BIOS settings.
5) The P-III/800 Coppermine runs really cool to the touch, and the whole setup is stable as a rock, even with the GeForce2. Ran for 12 hours without a glitch (after that, I gave up and powered down). What gives? I've seen notebooks with 800 MHz Celerons that run hotter.
6) I tried a Samsung SD-608 DVD drive with a dark grey bezel, but found that a standard white bezel Pioneer matched the brushed aluminum better.
7) I found a Logitech USB gamepad for $6.95, but haven't tested it with Linux yet.
8) The Adaptec Quartet PCI 4-port Ethernet card won't fit, so other solutions have to be found in case the Linux Router Project is being considered (looking for a half or 2/3 length PCI card).
9) The Osprey 1000 video capture card fits.
10) There's no CDROM audio cable supplied, but it's a standard type with the black 4-pin connector to the motherboard.
11) Still thinking up a wireless keyboard solution that mounts in the 3.5" bay for the floppy drive and connects internally to the KB and mouse ports - no easy solution in sight. The wire may have to be squeezed out through the hard-drive mounting bracket and plugged into the ports outside (very kludgy).