Power Requirements for SLI and OC'ing

Hey guys,

I am currently running an i7 930 and a GTX 470 on an Ultra LSP 750W power supply. I purchased a 9800GTX+ for PhysX and realized that my PSU couldn't push both cards (received boot problems). I also plan to get another GTX 470 for SLI, OC my i7 to atleast 4.2Ghz and still want to include that 9800GTX+ so I was wondering how much wattage should I look for on a new power supply as well as Amps on the +12V rail. Please consider that when OC'ing my CPU I will be buying a high end CPU cooler as well.
I was looking at the Corsair HX1000W PSU but I don't know if that would be enough or overkill. I was hoping to not spend more than $250 on this unit.

Current Specs:
Motherboard: EVGA X58 SLI LE
CPU: Intel i7 930
RAM: 6GB G.Skill Ripjaws 1600Mhz
HDD: 2 500GB Seagate Barracuda, 1 750GB Seagate Barracuda
Optical Drives: 2 Samsung Super-multi Drives
Case: Cooler Master HAF 932
GPU: EVGA GTX 470
PSU: Ultra LSP 750

Thanks.