Thanks to everyone that has helped me. I decided to go with the radeon 7950 cards instead of the 7970. It saves me $200 and with a difference of 0.02Mh/s/$ lower. I made my calculations with the 7970's I can hash up to 1400Mh/s if oc, with the whole system price of $1100 gives me 1.29Mh/s/$ spent. With the 7950's I can hash up to 1200Mh/s oc, with a price of about $930 for the whole system it gives me 1.27Mh/s/$ spent. So it's not a big difference it saves about $200 dollar. I will use ubuntu 12.04 LTS on a 16 GB thumb drive I already own.
I changed my mind, I will use milk crates, it looks pretty easy to do after reading some guides. Also swiched from msi 970 mobo, to asrock 970 and switched saphire vapor x to xfx.
http://pcpartpicker.com/user/thehulkk/saved/1wd1CPU: AMD Sempron 145 2.8GHz Single-Core Processor ($35.98 @ Outlet PC)
Motherboard: ASRock 970 Extreme3 ATX AM3+ Motherboard ($74.99 @ Newegg)
Memory: Patriot Signature 4GB (1 x 4GB) DDR3-1333 Memory ($28.87 @ Amazon)
Video Card: XFX Radeon HD 7950 3GB Video Card (2-Way CrossFire) ($263.98 @ Newegg)
Video Card: XFX Radeon HD 7950 3GB Video Card (2-Way CrossFire) ($263.98 @ Newegg)
Wireless Network Adapter: Encore ENUWI-1XN42 802.11b/g/n USB 2.0 Wi-Fi Adapter ($9.98 @ Outlet PC)
Power Supply: Cooler Master Silent Pro M2 720W 80 PLUS Bronze Certified ATX12V Power Supply ($74.99 @ Newegg)
Total: $752.77