Well, i'd say you've got to be awfully close to blowing it. They must really use high quality power supplies in those gateway systems. I'd recommend at least a 350w PS for that setup.
If its stable, and you don't plan on overclocking it, and don't use any usb peripherals, then feel free to keep it, I mean, if it isn't broken don't fix it. Of course, if it goes, it could take a lot of that hardware with it.
How are you running 3 monitors? Do you have 2 video cards?
Oh, and by the way:
WELCOME TO THE FORUMS
I hope you enjoy your stay here, and stay a while. These are the best forums I have ever come across, you won't find better anywhere else.
-CPFitz-
edit: gaaaahhh......that blue....its frying my eyes....