Plants for a 6 gall tropical tank.?

firstly, i am considering buying 3 pygmy corys and 1 betta. i also want some plants. i am a bit confused as at my lfs there were two categories, cold water and tropical plants. can u please give me a hand if java fern, java moss and hairgr are good and wat would u choose if i have already got driftwood with a plant on it. also wat type of lighting should i install if im on a budget? cheers