You can pick up the Sunlight Supply Sun Blaze at hydroponic stores (4 X 24W T5HO) for a decent price. These will need to be suspended above or propped upon the tank. Here is a link to what I am referring to (http://www.specialty-lights.com/sun-blaze-t5.html).
Good Luck on the hunt.
Stuart
Good Luck on the hunt.
Stuart