i use sun systems's hps 1kw with mh conversion bulbs and very satisfied with the company. their 250 should work well in a closet setting but i'd go with a switchable, remote ballast (toggle switch for both bulbs on the side of the ballast) and the 400 like mr 4bud suggests, it'll be easier/cheaper for future expansion....search em out at whatever webstore you're looking at or see them at discounthydro.com