What kind of light bulb should i use?

[thanhthui]

I have a 180 gallon fish tank, fresh water, with a few discus and im planning to buy real plants and more discus. but i want to know what kind of light would work the best/would look the best.
i need three light bulbs, i just dont know what kind.

also, can you suggest a few plant types that would look the best, in your opinion?

thanks :)