If you dont mind going external, the cheapest/coolest/quietest route would be a 1080 Phobya rad. This is as much good quality radiator you can get for the money. It can be fitted with four 180mm fans instead of nine 120mm for a virtually silent extreme cooler.
This also has the advantage of never needing more radiator, even if you put two more 290x's in there.
Oh and sorry for giant letters in op. Im doing this on my phone dont know what happened!!
Looks normal to me, sure you are not zoomed in?
A little googling showed me the case needs a bit of modding to fit a 360mm in the front and there is a specially designed 200mm rad for the roof by antec. Ideally you need both to cool both 290x's and a 4770k. You might be able to find a 240 that can fit on the exhaust of the case, but you will probably run into motherboard clearance issues. With this in mind, a 1080 external rad would be your best bet.
Component wise:
For the 290's, the reference EK waterblock fits them.
For the 4770k, the Supremacy would be good, a top performer at just £20 mroe than an entry level block.
For radiator the Xtreme 1080 Phobya rad (or the like) if you want to go external or a 360mm and the specially made antec 200mm for internal (higher temps, noisier and more expensive)
Fittings would be compression fittings of your choice (any from OCuk)
Primochill tubing of the same size as the fittings. (size has no performance effect, as long as tubing matches the fittings)
To link the GPU blocks, use two EKhd fittings and their pre-cut acrylic tubing.
Pump wise, go for the EK 4.0. It is cheap and easily could handle the finished loop.
Reservoir doesnt matter. Choose between tube and bay (although if you mod the case to fit the 360mm radiator inside, you probably wont fit a bay reservoir in there)
I can do a spec basket once you decide on whether you want internal or external and if you like fat tubing or thin.
