slim case power supply

i'm thinking about putting a new slimline gpu into my dell 531s case

(http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=4465554&CatId=3670)

and i was wondering if there is any type of external PSU boost available on the market, or what some good examples of slimline PSUs are. thanks

bump

The 531s has a TFX power supply, and the most recommended replacement for your system is the Seasonic SS-300TFX. It should be enough power for the GPU upgrade, which might bring your total power consumption to around 200W at load. You'd have to get a PCI-E power adapter to get it working. I don't know how well the card works thermally in your system, and if it might produce too much heat for your slim case to handle. I would risk it, personally, and you can always get a more powerful fan to compensate if need be.