Veg lighting question

Okay so I've decided to buy a digital ballast + 600 watt MH & HPS lights for my first grow. I would like to start the plants off in the veg room under the 600 watt MH but when the time comes to flower I would like to use the 600 HPS in the flowering room.

If I take the 600 watt MH from the veg room will the plant survive easily on any CFL lights I get? And how many CFL lights do I need in a veg room that is 4x2x7?

Thanks hope someone can help

anybody? I dont think its that hard of a question I am just a noob

depends on the number of plants, but i would never recommend florescents as they are a pain trying to keep ALL of them close enough. why not buy magnetic ballasts maybe a 400w MH and and 600w HPS, for about the same price of the digital. u plants would love u for not teasing them with florescents