If your using those CFL's i would get 4. One per plant. 125 Watts of CFL is enough to effectively flower ONE plant.
the better option here would be to get a Single 400 Watt HPS lamp and run that. HPS lamps give out avg. 100 Lumens per watt, and produse LESS heat than CFL's. CFL bulbs produce an average of 60 Lumens per watt, making for more heat per Lumen watt.
400 HPS Lamp will cost $100 and a 120 CFM Fan will Cost $70 but it will be WELL worth the money spent for the added quality of bud your going to get.
about 100 watts per plant
CFL's = 100 Watts per Plant MINIMUM. a plant needs 8700 Lumens MINIMUM to flower properly. 60 lumens per watt, 60x 125 = ~8,000 Lumens..... not quite enough....
which means 125 x 4= 500 Watts = 5 plants. 125 x 3= 375 watts. you would still need to add Light for every plant to get proper lumen output.