Lighting depends on what you what types of corals you want to keep. The 29 gallon instant ocean aquarium looks like it comes with regular flourescents. If you want to keep hard corals (
SPS) look for T5's or Metal Halides. I like the T5's since they don't affect the water temp as much as halides. If you want soft corals you could get by with power compact lights. Lights seem to be coming down in price (slowly) at most of the online retailers. Check out drsfostersmith or marinedepot or similar.
Take your time researching lights. Learn all you can about them since they are expensive and you don't want to buy a fixture that doesn't meet your needs down the road. Lighting is very important for many coral species.