help with building a desktop

[theVoidOne]

this is the first time im building a desktop. this is my current build:

-EVGA 012-P3-1470-AR GeForce GTX 470 (Fermi) 1280MB 320-bit GDDR5 PCI Express 2.0 x16 HDCP Ready SLI Support Video Card - http://www.newegg.com/Product/Produc...82E16814130550
-Sunbeam PSU-COM680-BK-US 680W ATX12V Modular Active PFC Power Supply - http://www.newegg.com/Product/Produc...82E16817709023
-Core i7-930 - http://www.microcenter.com/single_pr...uct_id=0331303
-ASUS P6X58D-E LGA 1366 Intel X58 SATA 6Gb/s USB 3.0 ATX Intel Motherboard
- http://www.newegg.com/Product/Produc...82E16813131641
-G.SKILL 6GB (3 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Triple Channel Kit Desktop Memory Model F3-12800CL9T-6GBNQ-http://www.newegg.com/Product/Product.aspx?Item=N82E16820231225
-HITACHI Deskstar HD31000 IDK/7K (0S00163) 1TB 7200 RPM SATA 3.0Gb/s 3.5" Internal Hard Drive - http://www.newegg.com/Product/Produc...82E16822145287
-Rosewill DESTROYER Black Gaming ATX Mid Tower Computer Case - http://www.newegg.com/Product/Produc...82E16811147144
-LITE-ON CD/DVD Burner - Bulk Black SATA Model iHAS124-04- http://www.newegg.com/Product/Produc...82E16827106289

do i need to buy anything else? are thing anything that are not compatible with each other?
is my power supply powerful enough for my computer, gtx 470? if i get two 470s in SLI, is it still powerful enough?
from what i heard, gtx 470 generates a lot of heat and requires a lot of power, do u have some other suggestions?
any suggestion would be helpful

 

[Trotter]

Everything is compatible.

I would grab these for cooling your CPU.
Newegg.com - Sunbeam CR-CCTF 120 mm Core-Contact Freezer CPU Cooler W/TX-2
Newegg.com - Sunbeam CR-LGA1366 LGA 1366 Core I7 Socket Retention Bracket Set

The card requires 550W by itself, so I doubt 650W will power two of them.