it will fit as the board comes with a PCIe16 slot but you will probably have a heck of a time finding a power supply that will fit. I think that the PSU will be too long just off the shelf. That mobo is the flipped from the normal and that is also VERY PROPRIETARY. My suggestion is to be very very comparing in looking at the existing PSU and at the deminsions of any that you buy. Dell is notorious for thier PSU to being built odd sized.
sorry banchan, not ALL of them are built the same size
You'll need more watts, probably around 400~500. I'm PRETTY SURE
that you can just buy a new PSU and put it in, since all PSUs are the same sizes.