I bought two T5 fixtures for my tanks on ebay. I bought the same "no name"
brand for both of my tanks. This is the lamp I bought for my 40B:
http://www.ebay.com/itm/36-T5-Aquarium-Light-234-watt-6-bulb-Timer-w-LED-Lunar-moon-T-5-New-2015-/281627533509?pt=LH_DefaultDomain_0&hash=item41924f20c5. While I can find the same light elsewhere, this seller is the only one advertising a
5 year warranty on the American-made Workhorse balast. I spoke with the seller, and he assured me he will personally handle any warranties on the lamps.
I really like the lamps, and the separate timers (moonlights, 3x bulbs, and 3x bulbs) work great. They unfortunately lose settings after a power outage (depending on duration). I don't have to reprogram them very often, but I keep a note with the time settings close by, just in case...
Edit: The ebay description says 4 bulbs on one timer, 2 bulbs on another timer, and moonlights on last timer. This isn't the case with either of my lights. Both lights have 3 bulbs on one timer, 3 bulbs on another timer, and moonlights on the last timer.