I am looking for something I can afford but will work also. 20x20 ok to heat with a propane garage heater? I am going to have ventilation. I am going with 8 lights. 3 on each side two in the middle. I will have it on a thermostat. I have thought about baceboard heating,a minin split which I do not want to do and a 1500 infread heater which I do not think will work. I have some cold winters here so am thining propane for long term and cheapest. any help is great.