Aeromotive sells a pump controller for their pumps. The current one is a 16306. They've had a few generations of them, and you can find used ones floating around.
They work by cutting the voltage in and out so many times a second, not lowering it like you'd think. The idea is as MAP says, to keep from pushing 800 lb/hr when you don't need it. Excessive heat can cause the aeromotive pumps to fail, and the pump controller will cut the flow down significantly below a point you set.
I would assume a well thought out fuel system would be okay without one, but I know the eliminator flows a lot more than the a1000, and I've heard more guys getting a pump controller with the eliminator. Call aeromotive- they'll help you out. Aeromotive told me I didn't need one for an A1000 unless I was going to be taking long road trips. The most susceptible time to excessive heat and pump failure would be with low fuel in the tank and an aeromotive pump running full capacity while cruising at low rpm for hours and not much fuel in the tank to keep it cool.