ideally u should go for a 400 hps with a cooltube if u can afford it if not then try a 250 hps i started on cfls but the problem with a single cfl like that when the plant is fully matured that 1 cfl will only cover 1 plant and even then u wont get lower buds because of light penetration so id invest cost u maybe 70 quid for a cheapo 1