GUESS WHAT???
So, on a whim I decided to remove the processor heat sink, and run the computer with the case open and a house fan blowing directly across the chips. Its been running for almost two hours now without freezing up.

Not sure if its the problem, but it hasn't locked up YET... If so, I'll buy some thermo-grease and reinstall the heat sink. It still has some on it, but there are a few bare spots. That would be amazing if that was the problem (overheating chips) and the fix was as simple as thermo grease. I'll cross my fingers. I'm gonna let her run till she pukes. If it doesn't, then despite wrecking two cars and breaking my cell phone this will be a good weekend! lol.