It sounds like it could be your BIOS/Motherboard or possibly memory, but unlikely as that would show a POST error. Have you plugged in all the power cords for your GTX 470?
I think you should go and get Killing Floor right now or GTFO! I have 14p on my debit card right now, do you think I will? There is just another option, GTFO!
I don't think that would be a good idea right now since you are really pushing the servers to its limit right now and you see that in the gameplay on the tf2 servers. But it would be fun with another server.