Beamswork leds are phenomenal lighting systems (I probably have the most experience with them on this site). Depending on the model you get they can come with either a plastic housing or a light weight aluminum metal. The 72" light does not sag in the middle, these lights are built very well and out compete the marineland single bright and double bright lights. The led120 and lower and higher models have a port on the opposite end of the lights that allows the addition of an external timer to control the whites and blues separate. If you are just looking for bright lighting for viewing fish go with the led200 and up models. They are single switch lights and are very bright.
Do you know if these lights will support a planted tank, possibly if the strips are doubled or tripled up?