If you are looking for in-sump, reliable, affordable, little head loss, and variety in gph look into Taam Rio Hyper Flo pumps. They are a huge improvement over Mag pumps,IMHO. The HF17 is 1090gph with 10' max head, at four feet would give you 750-800gph. Or if you want 10x turnover look at the HF 20 it is a little closer to 1000gph at 4' for less than $100. They have ceramic shaft and bearings ,don't heat up like Mag pumps, and use less wattage.