I'm not sure if you decided on a reflector yet. The ones from AH supply are very nice. I had 4 36 inch retrofit power compact kits over my 150 gallon. If you go this route, beware they edges are razor sharp. I cut myself fairly badly on one.
Sounds like you don't need to spend that kind of money on them since your tank isnt that deep, but thougt i'd throw in my 2 cents and say how pleased I was with mine.