on a 4790k I would say the Corsair H100i. I run it on a 4770k and get nearly an extra ghz out of the clock (4.4GHz vs 3.5 stock). Max CPU temp is about 49C at full load. Only complaint is that it can get a little loud, but it does a great job of keeping things nice and frosty. It will also fit fine in that Thermaltake case. You could get something bigger like the H105 or H110 but honestly that's just excessive.
Heard a lot of good things about the NZXT Kraken X60 as well, although I have no personal experience with it.