That's well thought out LED fixture you have built.
I've considered building a LED setup for my 120 gallon reef tank but shy'd away from it due to costs. With my increasing hydro bills, I'm now reconsidering my options again. Anything to keep the expenses low!
I have some technical decisions questions about you LED build.
Why XML not the CREES or Bridgelux LED's?
Why the 2 to 1 ratio CW to NW?
Do you know if the MW-90D-48 will work with your setup? How do you determine which MW LED driver is required for the setup?
Do you have plans to add royal blue LED's to your setup as atinics?
Where did you purchase your extruded aluminum pieces from?
BTW, how are you liking you Typhoon? I've just finished reading the Typhoon thread on another site. Will be submitting an order for the PCB's in the next couple of days.
Looking forward to your reply!