How serious of a booth you talking about??
If it's like most of us hobbist,you are talking about visquene or a sectioned area of your shop.
Building a high (above the floor) filtered intake using regular furnace filters,Poly or Pleated, Not the fiberglass type, with as many filters as space will allow should keep the incoming air clean.
I have 8-20x25, 2 high,4 wide. Opposite the booth from the ex. fan.
Door placement is important as well due to your in & out. You want it in an area where your airflow will pull to the ex. fan direct instead of ACROSS your work as you will allow trash to enter.
My ex. fan is an old belt drive attic fan 24X24 mounted outside the shop 24" above the floor in a sheetmetal box with a louver outlet. The motor is external to the box.
I use filters on the ex. fan intake but they get clogged so fast with material it's a pia to keep air flowing.
As for heat, Thats an expensive one.
Use whatever but just keep the "fire" out of the booth/prep area.
When doing small jobs, I shut the fan off as soon as the fog clears,then use a couple of the dual lamp 500w shop lights for heat/curing.
I just wait till warm weather for a whole car as I do this for "fun" and not a business,well, not a living anyway.
Wear a "sock" with the paint suit IF you have hair. It's amazing how much trash comes from your head.
I set off a couple of bug bombs if it's been awhile between jobs a day before painting as well as a bug zapper running at all times. Keeps the critter factor to a minimum.
Nothing like a spider crawling across your hood after the last coat of clear.