I have been following this thread with interest
Anyway I took the plunge and purchased a Radeon HD 4550 and installed it. I think this might have been a costly mistake because the Dell no longer boots. It just makes noises like a jet on take off and the power button glows yellow.
I have visually checked the capicitors on the board and cannot see any that are misshapen or leaking so is it possible I may have simply blown the PSU or am I looking at buying a new PC to fit around my new graphics card :(