Gaming build with the i5

Hello, I'm looking to build a new gaming rig and have come up with this build. I'm looking to buy all the parts this coming week and start building it by next week.

Case:
COOLER MASTER HAF 932 RC-932-KKN1-GP Black Steel ATX Full Tower Computer Case

Motherboard:
GIGABYTE GA-P55A-UD4P LGA 1156 Intel P55 SATA 6Gb/s USB 3.0 ATX Intel Motherboard w/ USB 3.0 & SATA 6 Gb/s

Processor:
Intel Core i5-760 Lynnfield 2.8GHz LGA 1156 95W Quad-Core Desktop Processor BX80605I5760
Processor cooler:
CORSAIR Cooling Hydro Series CWCH50-1 120mm High Performance CPU Cooler

Memory:
Mushkin Enhanced Ridgeback 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory Model 996826
GPU:
2x EVGA 01G-P3-1373-TR GeForce GTX 460 (Fermi) Superclocked EE 1GB 256-bit GDDR5 PCI Express 2.0 x16 HDCP Ready SLI Support ...
HD:
Western Digital Caviar Black WD1002FAEX 1TB 7200 RPM SATA 6.0Gb/s 3.5" Internal Hard Drive -Bare Drive
I also have a
OCZ Agility Series OCZSSD2-1AGT60G 2.5" 60GB SATA II MLC Internal Solid State Drive (SSD)
coming, but that's because I was able to buy it for 99 dollars.

I am pretty much set on these items except for the i5 which will be explained in my questions.

Here are my questions:
1. the i5-760. I was able to find it for cheaper at MicroCenter
And while I was there I looked at some of the i7s it seems as if they are cheaper then the i5 on newegg as well.
My budget allows me to get a processor around $200-250, and was wondering if any of those i7s they have would be worth getting over the current i5 that I chose.

2. What kind of power supply should I get?

3. And any other major parts am I missing? The keyboard/mouse/moniter/software etc I already have.


I'll be here most of the night waiting for some answers. Thanks in advance!