I know a lot of ppl that just use shop lights from a home depot type of store, I have a fully planted 55 gal tropical tank with a shop light and everything is growing wonderfully. I don't know the light requirments of saltwater tanks so i don't know if that would be an opition for you
Unless he's going to be keeping coral, a shop light will work too. It just won't look very pretty because you need a high color temperature saltwater bulb to enhance fish colors.