To be perfectly honest I would have koralias or aqueon powerheads all around. They are very adjustable, height and angle wise and no creatures can get sucked up into it, they have covers for the impellers. But thats just me. I would think 2 750's would be great in your tank. But if you don't have the cash you can just replace them one at a time.
180g Reef - 60g Rimless Reef -90G FOWLR- 125g Malawi Cichlids- 40b REEF- 34g Fresh Planted-working on- 20L FOWLR- working on
I have a mix of many different saltwater fish amongst my tanks, but I love my Tangs most of all.