Maximum PC

So I have been thinking about my wc setup for a while and just thought up an idea this morning. Right now I have a HAF X case running dual 470s and an i7 920 all under water. For cooling I have a single XSPC RX 360 rad being powered by an swiftech mcp655 pump. My ideas was to build a stand of some sort, something like the DD radbox to house two of the XSPC rads. I may also mount a 120mm rad in the HAF X in case I cant hook up the large rad array but still want to be able to run the computer. So i would still house the pump and res in the main case. The reason I want to do all of this is that I hate having the case cramped with the rad, it barely fits as it brushes the ram clips.
So my idea was to use an old power supply to power the 6-12 fans and a fan controller. Just a self contained cooling unit. The one thing I thought of that may be a problem would be my pump not being powerful enough. Any thoughts?

Have you considered mounting the rad to the outside of the case, rather than inside? You could put the entire rad+fan group outside, or mount each to either side of the case. (iow fans inside with rad out, or vice versa). It would be considerably easier than building your own external cooling tower (as I think is what I understand you're considering?).

Im kinda thinking it would be a fun project. I have seen the device that you mount off the back... I dunno haha. If I did build a separate tower then I can expand my cooling at the same time and be able to use the fans at a low speed.