I love my 16.5" sunpod. It's a 70 watt hqi, mounted on legs right over the tank, and it doesn't heat my tank up over 73 F. My tank is only 14 gallons. I've melted a few plants when I first switched too it, but now everything thrives.
and the bulbs are under 30 bucks, probably get a new one every 2 years. For the wattage, it's hard to beat those lumens