I'm going to be ordering a 36" 4 bulb fixture from catalina, which of course will be overkill for even a 40 gallon tank. Maybe a 1 or 2 bulb 39W T5HO fixture would work for you considering how shallow this tank is, if you were to go with T5HO.
This fixture would work good http://www.catalinaaquarium.com/prod...28eb4ee08e5b42
even though it isn't the new streamlined looking fixture, it's in your budget and should be plenty of light for you. You could use one bulb with a midday burst if you wanted. It all depends on how bright it really is.