So I've been trying to come up with a good two thousand dollar gaming rig for a while and this is what I've come up with. I should note that I don't do overclocking because I'm just not comfortable doing it. So check out the link to the build and leave any changes or opinions you would like, thanks for the help.
http://pcpartpicker.com/p/sLtjBm
-LinuxForYou
Seeing as you're not overclocking, you don't really need a liquid cooler. You could just pick up a cheap heatsink like the Hyper 212 evo to improve temps by a bit over the stock cooler, as well as reduce noise.
For RAM, I'm doubtful you'll need 16 GB in a gaming rig. That said, if you do want to go for 16, I'd recommend getting two 8 GB sticks instead of four 4 GB sticks. It allows for easier RAM upgrades in the future since there are two empty RAM slots and you don't have to get rid of any of your exisiting memory.
Also, for graphics card - with the changes to the cooler you could easily do R9 290 crossfire. It would be quite a bit more powerful than a 780 Ti (http://www.anandtech.com/bench/product/1075?vs=1072 yes that is 290x CF vs 780 Ti, but 290s are that much less powerful than 290xs). Of course, you'd then have all of the inherent problems with multi card setups, and you'd probably want to invest in a 850w power supply. But I do think it's a reasonable enough alternative to consider with this kind of budget.
I personaly just built a 2000 dollar gaming pc, so these are the parts in my system, that i recomment.
Proccesor: i7 4770k /Motherboard:msi gaming 7 atx/ Gpu:Gtx 780 sc 6gb/ Psu: evga supernova:850/ Case; corsaire 760t full tower case /Cooling: Corsaire H100i liquid cooler.
windows 8.1 proffesional and keyboard of your choice
http://pcpartpicker.com/p/BRj3gs
So beast