All depends on how you utilize the space, and what type of setup you use.
Just keep in mind that once you go into flower, the plants will at least double in size, and could almost triple with some strains. So I would say vegging to 3' could deffinitly be a problem. you need to Take into account the space that your reflector will take up as well. Also with that large of a plant, your not going to get much light penitrating through the canopy, so any bud at all below will be next to nothing.
If your planning on going from seed to harvest , you would be so much better off with a 600 HPS for that space. Much better yeild of larger denser buds. If your going with the cfls you need to figure out the lumens per sq ft. You have 5'x2'=10 sq ft. Optimal is 7,000 to 7,500 or higher lumens per square foot. If you figure by watts a minimum of 150 W per square foot for fluorescent's or cfls. It probably would'nt be practical with the amount of cfls you would need for that space. Check out craigslist and Ebay for a good cheap HID setup. Once you have your lighting figured out, I would suggest a SOG or Scrog setup with several smaller plants.
Seriously what I would suggest is slowly build your room as finances are available. Start with splitting the space in half, and start your first grow in the 2'-1/2'x2' area. For that space a 400 HPS would work great. You could have a nice little scrog with decent yield. as funds become available, pick up a 400 MH for the other space, and make that your veg room. This way you can keep a nice little perpetual grow going.
The filtered fresh air is always a good thing, so are the freebys from pop. Posting a couple of pics would be great.thanks for the advice ill have to research some lights and my dad has been doing hvac work for 20+ years and hes hooking me up with some free fans and duct work. my laundry room is next to my closet and it has a ac vent in it so im going to re-route it to my closet so i have filtered fresh air entering and im building a diy carbon filter for exaust. tell me if this all sounds good. as for seperating the room it has a small door on it unlike yours. ill have to take some pics to show you. the only way i could sepate it would be top and bottom and that might work.
Panda film is that thick plastic sheeting. black on one side and white on the other.panda film? what my idea is to get a metal storage cabinet and put it in my laundry room and make it my mother, clone, and veg cabinet. i just need to know about how tall do u keep mothers? or i could just clone my veging clones so i wouldnt need mothers. i would use cfls in the whole cabinet and use the closet for flowering with a 400 hps. that is the cheapest and easiest way for me to have two spaces. i think it would be worth it. Any advice on a bean supplier? im going to go ahead and order my beans and save my cash and build the two spaces.