It sonds like alot of space for 4 plants depending on how big you want your plants to be. Either way i would go with a switchable 600w MH/HPS lighting with a reflective hood that has a place for your exhaust. The 600 HPS produce more lumens than the 1000's do. Also if you dont have much height for your plants in your closet, then i would just put more plants in there If i didnt have much head room. Rule of thumb is measure the height of the room and then subtract 1ft-2ft for lighting between plants and lights, subtract the size of the plants you want, and finally measure and subtract the height of your hydro setup. The remaining space is for you decide what style you like most. I hope this helps:jointsmile: It will be cheaper to get the 600w and you will probably want to have an intake, it will never hurt you to have an intake or just get co2