Gpu
I would go with the ATI 5770, it has a low power consumption, its faster than the Nvidia 200 GTX series (I found this out the hard way...) and It is priced decently, I would definately recommend this specific one.
http://www.newegg.com/Product/Product.aspx?Item=N82E16814127490
It has good cooling, its silent, and a good deal faster than the other 5770's out there, this will play BFBC2 maxed out on a 30in display.
But if your looking to play in 3d (which would cost a great deal more for the 120hz Monitor, and 3D vision kit) and you want CUDA for professional purposes, I would recomend the 260 GTX, or the 250 GTS which is pretty much the same as the 9800 GTX+.
Of course the ATI card is gona save you alot more money than the Nvidia card, and even the card and 3D stuff.
ATI HD 5770 - $170
Nvidia 260 GTX - $200
Nvidia 250 GTS - $130, $150
or
ATI 5870, but beware. the older 4000 series from ATI uses alot of power, and they still experience driver issues.
CONCLUSION: The 5770 is going to be your best choice, I own a 275 GTX from Nvidia, and I have tested it personally against the ATI 5770. The 5770 has more memory, faster memory, A higher effective memory clock, and Direct X 11, This is the best bang for your buck, and you will not be dissapointed.
Thanks, and good luck with your computer
