Video Wall, driving maximum footage for the buck

I'm looking to build a rig to drive a video wall. I'd like the wall to be run from one machine for easier management. I'm planning to use cheap 24" LCDs as they have good area/$ ratios (slightly worried about brightness though?). I'd like the displays to be hardware accelerated (for video playback and such), but I don't expect to play high end games on them.

Driving eight 24" displays with four dual-dvi graphics cards should be easy, but can I go higher using just one system? What if I combine the four dual-dvi cards with matrox dual- or tripplehead-to-gos? Anyone has experience with this, or just thoughts? If you have more radical ideas, please share (projectors not an option).

Michael