Your setup will like be putting in about 2.0 wpg. Good enough for low light plants like anubias, crypts and java fern. Stem plants will have a difficult time growing.
As I recommended in another thread, I think you would be better of purchasing a Coralife 65w fixture from drsfostersmith.com. That will give you some room to grow stem plants better, plus it would look better then shop lights over your tank.
-John N.