Need Advice for First Build

Hey guys. This is my first time to the forums and I need some help. I'm building my first computer and was wondering if there was any advice on the parts I am using, such as compatibility issues, other options, etc.

The computer will be used mostly for heavy multi-tasking, with 3D CAD software, some video editing, and compiling software, but every once in a while I like to throw a game or two in So I'd like for it to be able to run Oblivion, COD4, Civilization 4, and maybe Crysis at good (not necessarily great) settings.

I plan on OCing my CPU to ~3.0GHz, and maybe adding another nVidia 8800GT in SLI.

I have already purshased the following for my current setup, and will be using them in my build:

- 1x EVGA 512-P3-N801-AR GeForce 8800 GT 512MB 256-bit GDDR3 PCI Express 2.0 x16 HDCP Ready SLI Supported Video Card
- 2x Western Digital Caviar Black WD7501AALS 750GB 7200 RPM SATA 3.0Gb/s Hard Drive
- 1x G.SKILL 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory

I am thinking about purchasing the following to complete it:

- 1x Intel Core 2 Quad Q6600 Kentsfield 2.4GHz LGA 775 Quad-Core Processor Model BX80562Q6600
- 1x COOLER MASTER RC-690-KKN1-GP Black SECC/ ABS ATX Mid Tower Computer Case
- 1x 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
- 2x LG 20X DVD±R DVD Burner w/ SecurDisc Tech Black SATA Model GH20NS15
- 1x Arctic Silver 5 Thermal Compound
- 1x ARCTIC COOLING Freezer 7 Pro 92mm CPU Cooler

My questions are:

1) What is a good MB to use (~$200) if I am looking to OC my CPU to ~3.0GHz and run my HDD in RAID 0?
2) Does anyone have any recommendations/comments/suggestions for changing or keeping my build?

Any help is appreciated. Thanks all!

Thanks. I'm looking at either:

1) GIGABYTE GA-EX38-DS4 LGA 775 Intel X38 ATX Intel Motherboard

or

2) ASUS P5N-D LGA 775 NVIDIA nForce 750i SLI ATX Intel Motherboard

Both are ~$150, but I'm able to spend around $200. So I was wondering if there was anything better out there for my setup.

And as far as RAID 0 not working so well for gaming, I figure I'm going to be doing a lot more data intensive work than gaming, which will run better with a RAID 0 setup..

The games are just for my down time