Comparing top of the line GPU's for 1440P performace:

[Burdock]

Hey guys! I'm finally getting around to making my self a new build after 5 years...
4770k water cooled with a h100i
ASUS SABERTOOTH Z87...
ASUS 1440p 27in slab of awesome
and so on...

Braging aside, I have been a bit indecisive about GPU's~
The main contenders are:
AMD 7990,
GTX 780,
GTX 770 in 2 way sli

The 7990 looks like the best price to performance in that range (5%ish less then the 2 GTX 770's) but I have heard it has some minor heat issues and frame pacing has not quite been fixed 100%

The GTX 780 I have heard good things about, but it just does not quite live up to the other contenders performance it seems~

And well... If I go the GTX 770 road I will have to cut 90$ worth of corners for going over my budget

 

[cars12345]

If you can, get the GTX 770 in SLI. Maybe you could buy one now, and save money to buy another later?
If not, buy the GTX 780.

The GTX 780 has better performance than a single GTX 770, but the GTX 770 has much better performance/price ratio.

EDIT: I forgot you mentioned 1440p. In that case, 2GB will most likely not cut it. Then, you should buy the GTX 780 with >2GB.

 

[Burdock]

I'm thinking if I where to go the way of 2 GTX 770's ~ I would get a pair of these.

http://www.amazon.com/Gigabyte-GDDR5-4GB-WINDFORCE-Graphics-GV-N770OC-4GD/dp/B00CU9GOAO

The only issue I can foresee is heat in my Fractal Design Define R4 Case~
Is that much of a problem??