Need help with LIGHTING!!!!

okay sooo i just bought 20 feminized seeds. 10 white widow and 10 grandaddy purp. im growing these in a room to themselves and was wondering if i would need more than one 1000 watt HPS bulb. but what im really needing help with is where i could find these fixtures at and which ones to get. soo some help on this issue would be great.

To grow 20 plants ya need a 1000 watter at least. If ya have the room get 2 and put 10 plants under each light. 9 plants fit better.