advice from vet growers

hey im new to growing and i only grow one plant at a time.(small budget) i have a plant that is about ready for harvest and cannot wait to start a new one, but this time i want a big plant with a big yield. ive been growing this plant with two 125w cfls in a dual socket. it has worked ok for this plant but i wanted to hook up more lights so i can grow a big plant. how many lights can i use and what wattage should they be? and also is this a dumb idea or will it work?my grow space is 4ftw X 5ftL X 8ftT

i just want to fill this room up with one plant. just be honest i grow for just myself and my buddies and im having a lot of fun growing. im the only one out of my friends that has been successful with growing. they dont use this sweet website. any advice is greatly appriciated.

one plant, man that stinks. what if you get a male? Anywho- if I had an 8' tall grow room and could only grow one I would grow a durban poisen plant. Good Luck!