For a FOWLR 180, I would think the 90 LED kits would be good. You are running 320w of lights and the 90 LEDs would be a little less, but the the lenses would give good spread over the tank.
I bought the 36 LED kits and just finished installing it over my 40 gal breeder using U channel from Lowes. I was very pleased with the result. I used all the kit parts right down to the wire connectors and I did not find anything that I thought needed to be replaced other than maybe the potentiometers. They tend to dim the light in large increments and do not have much fine adjustment. I read where someone replaced these with Radio Shack parts and the fine adjustment worked much better. I think I may change these out with the Radio Shack and see if it makes a difference.
After running 12 hrs, the aluminum was barely warm to the touch. The drivers were some warmer, but nothing approaching hot. I put spacers behind the drivers when I mounted them to provide cooling all the way around. I built a canopy enclosure for the U channel and mounted everything inside with two 120mm fans for cooling.
Here is the light over the tank, the U channel with LEDs attached with the material in the kit, and the layout of the 36 LEDs on the U channel. I bought the 18 white, 14 blue, 2 red, 2 UV. Not much in the tank yet, it mainly houses a mated pair of yellow head jawfish. I am considering coverning the 8 bulb T5 over my 120 gal to LED and just wanted to build this kit to get some exposure to DIY LED. Hard to beat for $126 landed at my doorstep.
