If you are on a budget, don't buy a premade sump. Make your own. Get the biggest aquarium you can fit in the stand, and put in baffles made of plexiglass using silicone.
For filtration, if you get a sump, I'd recommend an Octopus skimmer. They are the best bang for the buck. And lights, you can either go with T5s or metal halide. You'll have to weigh the pros and cons of each to decide what you want.