do i have enough power?

I've been thinking about upgraded my graphics card for awhile now. I've been holding off since I'm not sure if my PSU could take on the card. My PSU has a MAX output of 364W, but it can't exceed 291.6W on the 12V rails. The 12V rails are rated at 12A. Do ya think I have enough juice to run a BFG Tech GeForce 8600GT 256MB GDDR3 PCI-E card?
http://www.newegg.com/Product/Prod [...] 6814143105

I currently use an ATI radeon x300. Just trying to get an upgrade in my frame rate until I can save up to build a whole new rig myself.
Thanks.

I figured that was what I had to do. It's a sony vaio though, so it has proprietary components. I don't really want to spend the money to get a new psu and move everything to a new case, since I don't think it would fit in the one I have now. I'd rather build a whole new comp.

Thats what got me into building machines, frigging companies using proprietary parts, so you cant upgrade easily (or on the cheap). If your box is older (2 or 3 years) I would save up $1500 and build a new machine. Then sell the Vaio on eBay to recoup some of your expenses.

I'm not sure what to do since one of ya say it probably wouldn't work and the other says it would work. I guess I'll just hold out and just wait until I can build my own.