Does anyone know where to get a rheostat that can control 90w @ close to 8 amps? I need it to control my fans for the CPU rad I'm about to add to my main system, and the fans aren't attached to the PSU, they're on a separate DC power supply. I need to be able to turn them down for gaming and up for OCing, but a single knob (or two knobs, either way) is what I'm after.