Re: intercooler water route
The best method is to simply run the lines in parallel. You can either run two pump directly off the ice box, or one large pump and Y it to each intercooler, then Y it after each intercooler back into the heat exchanger. Or run two pumps, and two heat exchangers, back into one ice box.
Problems with one pump is that each cooler will only get 1/2 of the required volume that the pump will put out. You really want as much flow through the cores as you can, less volume of water doesn't remove as much heat as twice as much water through the core. Within reason, of course, no use pulling 60 amps just to run your intercooler pumps
Make sense?