Hey duke I have a marineland reef capable led light that's 16" if you would want to try. I had done a par test and it actually puts out more then it is said to. Pm me if you are interested.
check out rapidLED if they dont have a fixture you may still want to email them as they are very helpful and may help you out with the best size or maybe make one just for you
Two bars, 36W, separate channels for royal blue and white, with splash guard, built to order(you can switch one one or two diodes to other color), $200