Additional Flow for my tank?

[DarkHorseMBA]

I have 75G tank, and the return pump is gibing about 650/GPH account for head length. I since added 2x KORALIA Nano's @ 425/GPH each.

Big Al's online has 50% all KORALIA EVOLUTION pumps, that's where I go my Nano's before. I'd like to add some flow, but I'm not sure if I should order 2x750 or 2x1050 or some other combo.
My tanks is still newish, has only one fish, a small Zoa frag and mushroom. I plan on hard & soft corals and more fish soon, but I'd like to take advantage of this sale now.
Any idea's on what or how much to add?

DarkHorseMBA

[jrsatx20]

In a 75 I would put 2 1400.