a real option is to get a computer case that will support a good thick 360mm radiator and get a good rated pump and parts. once you have that, it should last nearly forever if you take care of it, besides changing out cheap tubes every now and then. now once you have something like that, you just upgrade cards and get blocks to go with them. a 780ti kingpin under water at about 1.65ghz will match 2x770's at 1150mhz on air. the only difference is that you get to keep the water if you want to upgrade. but if sli is your thing then trying to water cool two gpu's the right way will require a 480mm rad and most people are not that extreme.
I like to think I am, but i'm probably not... I just know a lot about pc's!
thanks for the advice and its gonna be used when i'm buying!