KMC Forums - Will my PSU hold me back? (upgrade question)

Hey guys, as I wrote in a previous thread I have plans on buying a new GFX when I go to Italy next month, now I have plans on buying a 285GTX but I am not sure if my PSU will be powerful enough. So I hope some of you here in the computer forum might be able tell me that.

My current system looks like this:

Intel Q9550 Quadcore 2.8ghz + XIGMATEK Achilles CPU Cooler
4x2GB = 8GB DDR-2 Dual Channel 800Mhz RAM
NForce 650i SLI Motherboard
1x500GB (Some western digigal HDD)

I believe there is 2 case fans aswell, and some lights in and around my case.

The current GFX I have is a GeForce 8800GT 512MB Ram, I have been up til now using 2x GeForce 8800GT 512MB running SLI, but one of them has now a RAM error and my 1 year warrenty on the computer is out. So now is a good time to upgrade anyway.

When I buy the 285GTX I was hoping I could use the GTX as my main card obviously and then have the 8800GT as dedicated PhysX card, But here is the question:

Will my current 750W PSU be enought to handle that considering my hardware. I know I ran 2x8800SLI without any problems, im just wondering aobut the GTX+8800GT

Thanks for your help guys.