are you going to be able to vent out heat from that closet. no matter what lights you use (cept led) it is gonna get hot. being a closet grower you're prolly looking to keep things on the DL and unless you can install ventilation (intake van and exhaust) you're going to have a tough time managing temps in the closet with the door closed. If you can leave the door open when the lights on and allow plenty of air to get in you should be fine.
For lighting, consider where you will put you ballast if you consider HID lights. The ballast gets pretty hot and I wouldn't recommend putting it in the closet b/c you'll already be putting plenty of heat in there with a bulb. Good places are in the ceiling or hidden in the room.
To do a 5x2 area you're looking at 400 watt hps at least. Esp for the yields you have in mind. The light won't be able to reach the entire 5 feet so you'll either want a light mover ($200+ some places or DIY) or add CFLs to the outside and rotate the plants a lot
I'm a DWC grower and have seen other good success. I doubt you can fit 8 5gallon buckets in 5' and still have room for plants that will bring in a P. Either go SOG DWC with big totes/trays or just good old dirt in pots.
It can get spendy and if you're on a budget make sure to put money towards a light before anything else. If you want to pull a P you won't do it on crap lights. Spend the few hundred bucks extra and be amazed
If you're on a budget check out the CFL subforum and look into the Buds For Less CFL Grow Book. You can get it at most Barnes and Noble stores