Do NOT run those Koralias on a Red Sea wavemaker, it will break them. Koralias are not meant to run on wavemakers like that one, they can not handle the constant on/off. Koralia now makes their own wavemaker (although rediculously expensive) as well as special "wave maker" powerheads. Just a heads up. I recommend you look into an OM-4way (Ocean Motion). They are 100x better than a SCWD like I went with, as long as you have 4 closed loop return holes.
As for a pump, I have always heard and seen good things with the sequence dart pump. I went with the Gen-X because of the price though and I am extremely happy with the output and noise level.
Are you talking about a closed loop pump or a return pump, big difference in output. Return pump you probably don't want more than 1000GPH on that, but closed loop you could easily do 2000GPH without problems as long as it is plumbed right.