The best lighting for 20g nano reef tank

I have 18"x18"x18" so about 20 gallon nano tank. I want to put bta in the tank. The set up right now is 20 lb of live rock and bak pak 2 protein skimmer (on the side). I'm looking for clamp led lighting on the back because the skimmer took the most space on the left side of the tank. My budget is up $100. What clamp led light can you recommend for bta?

I have found this and not sure if it is enough:
http://ift.tt/1qJbxoQ