I've heard good things about finnex ray 2 series fixtures. I just got one for my 20 gallon and can't wait to see how it does. I don't know if you have seen this but this thread has a great deal of information on several current fixtures available.
LED Lighting Compendium
I have the 24" ray 2 DS fixture and going by the information on that thread it should give me medium to high light for my tank. Hope that helped.