Also i'm confused which 780's to get. Reference or non reference? I've heard non reference cards dump hot air back into the case whereas reference ones don't. Is that true?
In simple terms... Yeah, a lot of them (if not all) do.
Some have a bit of a rear vent, but there's so much space around the sides of the heatsinks and so much air being blasted on to the card that a lot of it goes out the sides.
But that's where your case fans come in. IIRC, aside from looking wicked, your 600T can fit 4x 120mm fans on the side panel, has 200mm front intake and top exhaust (the latter of which can accomodate 2x 120s instead), plus another 120mm rear exhaust?
That's pretty hefty on the positive pressure side...
Heat does not rise, as many people claim, but hot air does. Cold air displaces warmer air upward and most of your fans are pushing cold air in, which will force the warm air up and out. Not really very scientific an explanation, but that's basically how it works.
So in short, if your current cooling is good then it shouldn't be a problem.
As for the card - Generally non-reference ones have better coolers and more features, like overclocking ability... generally. There are always exceptions.
A pair of 780s in SLI will be utterly awesome, possibly even considerable overkill, unless you're planning on trying for an overclocking record.
I only have 1080p myself, but most enthusiasts I know personally with 1440 still only have a single card and are chuffed to bits as far as general gaming goes. One has a single 780Ti, which is the next level up and pretty much top of the board as far as Nvidia graphics cards go.
It all depends what you want to do with this build and how much you want to spend.
Another that was recommended to me was the EVGA GeForce GTX780 Classified.
I personally chose the MSI GTX780 Lightning, which is astounding anyway and overclocks very well.
You may also wish to consider the AMD range of R9-280s and R9-290s, both of which come in standard and X versions, also top-end cards.
