cutting the tips makes it split into 2, but adds extra time to recover itself. easier to have an extra plant really...

lights: soft white is good, but warm whites are even better. ditch that halogen and buy another 4 warm white bulbs, since you should have 3 per plant ideally.

also, make sure the cfls are within 2-4 inches of the plant to ensure maximum light reaches it.

PS: expect your plant to gain 1-2 feet in height during the first month of flowering, if not more. looks healthy tho, good luck!