Nice grow man, i have a frend that dug out under his houes and did sum prity big grows meany years ago,
how meny CLF'S are you going to use for flowering? as i would get all that i can in there? i grow sum lovely bud with sum CLF's years ago, you just need lots of lights, and keep them real close, 1-2" away.
What are you doing for venting fresh air in?
one more thing that foil under your plants will be ok for CLF growing, but dont use it with a HID light, as it will burn shit out of your plants in no time.
Good luck.