Re: 250W PS with a Radeon x700 Pro
I would try installing the video card first to see if the motherboard will automatically override the integrated video controllers. I think it should be ok. I installed an AGP video card before on someone else's PC that also was using integrated video. I just popped it in and turned it on. Bam, it worked.
*Fact: Microsoft Window's Blue Screen of Death vs Computerforums.org's White Screen of Death. Which is worse?