It's enough but do you want a monstrous end product or just a so-so product? If you want monster cola's you will need more before you're done especially for 3 plants in that large of an area. Your grow area is 10 sq ft or 50 cu sq ft. That's a lot. My grow area is not even half that size and I use more CFL's than you currently have. To be amazingly effective you would need way more lumens than that spread evenly across your tent and the light producing those lumens either high powered enough (so that they penetrate deep within the canopy) to remain stationary over top, or enough bulbs to where you can dangle them all over your plants because CFL light couldn't penetrate a wet paper bag and grow a piece of grass. You need them to be close to your plant at all times to be effective.
My advice? If you are going to be flowering with an HPS anyways why waste your time and money? Just buy a dual MH/HPS switchable ballast with a vented reflector glass-sealed hood and a couple bulbs for like $300-$400. While it would work, it doesn't make much sense to veg with CFL's (specifically a low number of CFL's at that) and then flower with an HPS. You might as well veg with an MH and flower with an HPS and have way better bud all other things equal. The only reason I would consider what you're doing is if I had a hook-up on a single HPS (let's say cheap from a friend so it makes sense to buy it) or if I already had one lying around not being used.
EDIT: Also I'm not trying to knock your idea. I'm just saying that's what makes more sense to me. If you are dead-set on using your current plan which is CFL to veg and HPS to flower, then just try to get an HPS the cheapest route possible, and increase your number of CFL's to get those plants some light. You'll be alright. Either way you are going to be really high in a few months so whatever works out better for you.
