PRIM*Time

Rustoleum 2x "Wet or Dry sandable primer, you can generally find the primer at a Home Depot hardware store.
The trick to a nice coat in my experience is to SHAKE WELL & WARM the can, either by sun light or a space heater - but please use caution when heating with a space heater. the recommended temperature is on the back of the can along with the instruction.
First a light coat of primer to find any anomalies that may have been missed during the customising process.  After any anomalies are fixed the next step is to lightly prim another coat of primer, let set, lightly low grit sand paper - still checking for anomalies. 2 or 3 coats of primer should be sufficient.  Again light low grit sanding sponge & buff with a sock like material. special note* watch for lint when using material as a buffer.  Let model set at least a day in between Prim*times & 3 days to cure before painting or shipping.
As a preference I do not use spray boxes, they seem to create more work do to the spray back. A well ventilated area from cool breeze works great.
I do date my primer cans so they are used newest to date, & i do not use the last bit of primer in a can, it reminds me of the last bit of drink in the bottom of a pop can. Yuck.