Got the Saphire gfx card in the mail on Friday and installed it last night. It was a really tight fit with the tiny case, but the card's fan ended up in a perfect place to take advantage of the vent holes on top of the case. It ran Red Orchestra II Beta (at about 90% graphics settings) very smoothly, and no power crashes. It could not quite keep up on more complicated maps at maxed out settings, and still had no power issues. The card is surprisingly quiet, and so far seems to run fairly cool.
WE went from 3.2 to 5.9 (limited by the disk transfer rate - the card is a 7.4) good enough for my needs.
Thanks for the suggestion.
Another happy customer.