How about using reflectix foil insulation? You can tape it together, it's reflective and great thermal insulation.
I wouldn't buy any more fluorescent lights.
I use a cooling tube on a 400watt bulb in an area 4' x 30 inches to 30 inches to the bottom of the light.
If you can use a high pressure...
Hi
I'm a retired guy in Canada. I've smoked for 38 years, and grown my own for the last 20 or so. Just for me. Enough to feed my head...continuously. Currently growing in an area 4' x 30 inches x 30 inches to the bottom of the lights. Totally automated; can and do walk away for long periods...
I'd set up a fan and carbon filter to reduce the smell in the closet.
My brother has a tent and filters it, and you can't smell a thinf if you're right beside it.