Get rid of that massey 4 fan for your exaust i had the same problem. I replaced it with sunbeam 10 inch one also at walmart for 15$ and put the fan inside your box. my box is a little smaller but my temp droped 5 degrees or more.
The plants should be bigger i got 3 nodes in 2 weeks with 1 42 6400k each plant with a temp like that you should be able to have the lights very close around 2 inches away works well for me with good air flow. Flowering well that bepends on the space you have plats will double or triple in size...
You will be able to grow some good smoke just not dank nugs just have 4 or 5 26w bulbs very close to the buds 1 or 2 inches depending on Temp and air flow closer you get with low Watts the better a light meter will prove this just dont let your baby's burn
HI Nemanja that really depends on alot of factors but if you are just doing a small grow 4 to 6 plants with limited space 5-5 closet cfls will do great. I recomend high wattage 68+ for flowering i use 2 105w 2700k for side lighting kolas since cfls have low light penitration and 4 68w 2700k for...