Placement of power heads??

[AJ_77]

Maybe this article will help you decide:

http://www.advancedaquarist.com/2007/1/aafeature/view

You could use the 4 to generate alternating directional flow, 2 at a time. What intervals does the Wavemaster support? I'd think that with 2x1600 gph (or whatever the modded 1200's are rated) would work just fine, with two in oppostion for the alternate pattern.