I'm planning within the next 8 months to have a nice HAF X case while water cooling my CPU (I will get a Haswell i5) and my 7970 (which I plan on overclocking both). The thing is that I have the XSPC Raystorm 750 RS240 which means my pump is a nice little dual bay pump/res combo (I really like the look of it). Although what I plan on doing is:
1. Get a Haswell CPU with a motherboard.
2. Get A HAF X case (also order some extra tubes).
3. Water cool my 7970. One thing I would like to note is that I have a Vapor-X edition and after asking a person at frozen CPU we decided that I can get a uneversal GPU waterblock and some little heatsinks for the RAM. The only thing I worry is that the VRMs have a little heatsink on them already but I'm not sure if the stock heatsink it keeping them cool.
4. Possible get a triple radiator for the top of the HAF X and externally mount my current dual radiator.
So after all this do you think the pump will have any problems?
My idea of a stable GPU overclock is to set the voltage to the max and then keep clicking the "Add 1MHz" button until your finger gets tired.
Sounds like a good way to run a card hotter than it needs to be.
The pump that comes with the kit (an XSPC X20 750L, V2 or V4 depending when you got it) should be enough for what your after.
If your looking for a triple rad to mount at the top, recommend a slim one.
Personally think an XSPC EX360 Crossflow would be a good one to get. Its slim and due to the location of the ports it will cut down a fair bit of tubing.