Best Hardware/software options?

[pahchay]

Hey, it's been 5 years now since I finished my full standup MAME cabinet.  I built the whole thing around a really cool silver PC case with a flip down concealed front panel.  The problem is, my onboard video card died and I'm left with either having to find an old video card to get it working, or do a more significant upgrade and do the whole motherboard, and operating system, Hard Drives, etc.  I mean, I put way too much work into the cabinet to have it limping along with a board that is falling apart.  I want to be able to emulate the latest consoles, and maybe be a game station that will output to a flat screen for Wii, etc.

I know the whole point is go go "Old school" but I don't have the time to keep bandaging things together.

Does anyone have any suggestions on a good ATX motherboard, and operating system to run the MAME program front end?

Thanks!