I think you heater should be close to the ground.
Then you need a ceiling fan to circulate the heated & cold air
as far as painting in the dead cold .get it warm check it with a laser infrared thermometer & make sure that your intake air is pre heated.
do not leave any thing that can generate a spark on.
Those oil filled radiator heaters work real good at making radiant heat.
Do some experimenting before you go for the "money shot"