Will this gaming computer work?

^ First off, the CPU and the mobo are incompatible...The CPU is a LGA 1366 and the mobo LGA 1156...
When are you planning to buy the PC ?? You should know that Intel is going to launch newer CPUs by Jan 5th, so waiting might be a good idea if possible,...

Conclusions

The Radeon HD 6870 and HD 6850 are both excellent cards, and offer an amazing price/performance ratio. In my testing, the Radeon HD 6870 offered approximately 95% of the performance of the Radeon HD 5870, for 64% of the price - all with lower heat, noise and power.

The Radeon HD 6850 performed offered approximately 85% of the performance of the Radeon HD 5870, for 48% of ther price. The HD 6850 vs. HD 5850 comparison held ot that of the 6870/5870 - 95% of the power for 64% of the price.


The New Cost of Eyefinity

I year ago, the entry price for a high-end Eyefinity setup was $400 (or more, based on demand) for a Radeon HD 5870, and another $125 for an DP > Dual-Link DVI adapter. This was approaching $525 - just for the GPU. If you needed extra monitors, the cost went up significantly. Today, you can get a Radeon HD 6870 for $239, plus $25 for a DP > Single-Link DVI adapter. This puts you at less than $275 for what is essentially the same performance. Saving $250 on your GPU setup is a major improvement in affordability. That money could be put towards a CFX setup, the 3rd monitor, or left in your pocket.