First gaming build please help.

Approximate Purchase Date: 1/31/11

Budget Range: 600-700 (including OS)

System Usage: Gaming (SC2, Fallout NV, Guild Wars 2, and Diablo 3)

Parts Not Required: keyboard, mouse, monitor, speakers

Preferred Website(s) for Parts: None

Country of Origin: USA

Parts Preferences: AMD CPU

Overclocking: Maybe

SLI for now Maybe Crossfire in the future

Additional Comments: The parts have been tentatively selected. Please let me know if you see any issues or anywhere I can save a few dollars.

Case:
NZXT GAMMA Classic Series GAMA-001BK Black Steel ATX Mid Tower Computer Case
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

HDD:
SAMSUNG Spinpoint F4 HD322GJ/U 320GB 7200 RPM SATA 3.0Gb/s 3.5" Internal Hard Drive -Bare Drive
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

*MOBO* Update (thanks rolli59)
ASUS M4A79XTD EVO AM3 AMD 790X ATX AMD Motherboard
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

Network: Wireless is required.
Rosewill RNX-N180PCe PCI Express Revision 1.1 Wireless Adapter
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

GPU:
HIS H577FK1GD Radeon HD 5770 (Juniper XT) 1GB 128-bit GDDR5 PCI Express 2.0 x16 HDCP Ready CrossFireX Support Video Card
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

CD:
SONY Black SATA DVD-ROM Drive Model DDU1681S-0B – OEM
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

*PSU* Update (thanks rolli59)
Antec EarthWatts EA650 650W Continuous Power ATX12V Ver.2.2 / EPS12V version 2.91 SLI Certified CrossFire Ready 80 PLUS Certified ...
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

RAM:
G.SKILL 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1333 (PC3 10600) Dual Channel Kit Desktop Memory Model F3-10600CL9D-4GBNT
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

CPU:
AMD Phenom II X4 955 Black Edition Deneb 3.2GHz Socket AM3 125W Quad-Core Processor HDZ955FBGMBOX
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

OS:
Microsoft Windows 7 Home Premium 64-bit 1-Pack for System Builders – OEM
http://www.newegg.com/Product/Product.aspx?Item=N82E168...


TOTAL COST $705.90 before rebate $645.90 after rebate

Any thoughts?

My concerns:
1. Will there be any problems with the network card
2. Will everything fit in that case including future crossfire?
3. Is the PSU of sufficient quality?


Thank you for your help,

Joe