options for A closed loop system?

i'm using two of those strainer drains to draw the water out of the aquarium. I want to use an external pump for this because my sump will be very full.
I'd like to split it to three (3) different returns to the main tank. what pump could i get that's under 200 that would give me good turnover out of three seperate returns. Each individual return will rise about 4 feet to the loc-lines. So i'm thinking the pump needs to be atleast 1300 gph. ANy suguestions?
Also would i need to put a check valve anywhere on a closed loop? I have an inkling that i just asked a very dumb question, but i'd like to be sure.
75 and sunny in L.A.