New to building, a few questions...

Hey everyone... I've been looking for a new computer and almost bought the HP BlackBird 002 for $3000 but decided to build one better with the exception of liquid cooling for half the price.... Now, I've got everything picked out except a motherboard (cant decide) and a sound card..... So Here's what I picked out, tell me if everything should go together good and WHICH MOBO/SOUND CARD SHOULD I GET?

Case:
Thermaltake ArmorPlus(Armor+)

Processor:
Intel Core2 Quad Q9400 2.66GHz

Power Supply:
PC Power & Cooling S75QB 750W ATX12V / EPS12V SLI NVIDIA SLI Certified (Dual 8800 GTX and below) CrossFire Ready 80 PLUS Certified Active PFC Power Supply

Video Card:
http://www.newegg.com/Product/Prod [...] 6814130400

RAM:
CORSAIR XMS2 4GB (2 x 2GB)

Hard Drive:
Western Digital Caviar SE16 WD6400AAKS 640GB

ROM Drive:
ASUS Black SATA DVD-ROM Drive Model DVD-E818A3T

CPU Cooler:
http://www.newegg.com/Product/Prod [...] 6835118020

MotherBoard(s) (which will be the best for my set up:
http://www.newegg.com/Product/Prod [...] 6813131219

or

http://www.newegg.com/Product/Prod [...] 6813188024

And what sound card will be a good one and work?

The total for all over this is around $1,400... I dont want to go over $1,500 so all I need is a sound card and Im set right?

How good will this build be and is there anything else I need to know before I buy / assemble everything? Thanks!