I had it with these MJ1200's

You might want to try using a wp25 and supplement with your two mjs for more random flow.I use one wp25 and one evo750(which I already had) and it works pretty well but my tank is a 40b and is a mixed reef with only a few easy sps.If I were keeping mainly sps I would want another wp25.AS far as the sand blowing that's some thing you'll just have to work out if you want a high flow sps tank.When I set my tank up I used sugar fine sand and it was a real problem,so I removed a lot of it and replaced it with a coarser sand.

 

I was thinking exactly that to use a wp25 along with a maxi jet. The sand however has to go in my tank. I have a bag reefrocks.net that I haven't even opened up. Curious if that sand is a bit coarser.