This is the summary of a review i found that pretty much sums up my feelings on it.
The question here then, is whether all else is actually equal - While the GeForce 9800 GTX+ is a competent piece of hardware that really doesn't disappoint in what it offers any potential buyer, it's hard not to cast envious glances across the aisle at AMD's Radeon HD 4850 part, which can generally match or best the GeForce 9800 GTX+ at 1920x1200 with 4x anti-aliasing enabled, while also proving to be somewhat cheaper than XFX's offering here in the process. Personally, given this choice I'd lean towards the Radeon HD 4850, but if you find the GeForce 9800 GTX+ Black Edition's features and bundle more tempting then I can't say you'd be disappointed with the performance it offers either.
Review,
http://www.elitebastards.com/cms/index.php?option=com_content&task=view&id=637&Itemid=27
Now according to this review.
http://www.xbitlabs.com/articles/video/display/palit-gf9800gtxplus_5.html#sect0
The power consumption is actually less than the 4850 due to the card being as i suspected a 92b 55nm chip.
On that evidence it would run ok on your power supply but im afraid i wouldnt go as far as telling you it will be fine. Thats down to the need for 2x6Pin PCIE connectors which your PSU dosent have.
So really its up to you to decide if you want to take a chance with the addaptor or not.
Mactronix