ALGAE
I think it'll work out if you make sure you are NOT overfeeding and keep to a rigorous water change schedule while things finish settling in, but the inadequate flow is going to make it harder and it will take longer.
And based on the algae, it's possible your sand bed and rocks have already been saturated with detritus. Check around in the sand and blow some water though the rocks at close quarters with a power head to assess the situation. It's possible additional action will be required.
You may also want to dial back your lights to the minimum needed for your corals until things are more settled as well. Using a lux meter, get closer to 10,000-20,000 lux. If you can't dim your fixture, then limit the hours per day to around 4-6
FLOW
I'm afraid the flow situation is going to cripple you going forward and your present solution may be inadequate.
First, to avoid creating other issues you'll want the keep the flow through the sump limited to that necessary for filtration/to feed your skimmer. Two to four times your tank volume - or 600 to 1200 gph - is completely adequate. More, or even the top end of the scale, doesn't really gain you anything as it's way too little flow to help in the display tank, so use it as an excuse to save a little power and cut back the flow.
The main thing going forward is that 26"H isn't a lot of room for the MP60's to work and it's a very long tank for vortech (or Hydor) style of pump which has a very short, stubby flow pattern. Especially considering their cost ($1300/pr), I'm doubtful you will get adequate performance without adding more pumps.
I know you said you already ordered, but....I'd consider instead using a set of one or more Tunze 6105's (for their longer, narrower flow), possibly with a wavebox as well instead of what you have coming. I think 2x Tunze 6105's and a 6215 wavebox, or just the wavebox extension if you have a controller already (only $1100-$1200 if you source everything as new) is where I'd start...perhaps get three or four 6105's ($1000 or $1300) and skip the wavebox if waves aren't your main focus. The 6105's alone will still be able to generate a significant wave.
I hope this helps! Lemme know if you have more quesitons/concerns!
-Matt
P.S. That's gonna be a beauty of a tank!