The CPU you selected is overpriced, either go with the 955 or better yet switch to a Core i5 750. I would go for a 5850 instead, or if you're intent on getting the 5870 get the XFX one. You want dual channel RAM (4gb) because triple channel is for x58 motherboards. If you pick the i5, be sure to get the low voltage type. Get a different HDD, check out the Spinpoint F3 from Samsung. Get a smaller PSU such as the TruePower New 750W. Finally, you simply must get a new monitor, either GPU will be complete overkill at that resolution.
Jbakerlent gave you good advice looks like, but without quite reading it all I'll give you a few thoughts.
Your monitor resolution is rather small by todays standards, and the GPU you selected is massive overkill. If this is a CRT you need for your design work, consider a separate monitor for gaming or downgrade the GPU.
The PSU is also a bit overkill. Even two 5870s will run fine on an 850W.