The main critical factor (aside from cost) is the lumen per watt ratio. HO T8s are not as efficient as 'regular' T8s. 2' Linear T5s are not as efficient as 3' or 4' T5s.

For a small space, consider going with T5 biax/PL-L bulbs. They are essentially a 4' bulb folded in half (U-shape) to fit in a 2' space.