Just about any of them should work for that small an area. We used to heat a shop with wood. I'd suggest adding a magic heat to the pipe to increase efficiency and circulate the air.
If you take someone elses money to do it then I say they should be entitled to access it. I get what you're saying but I saw way too many people sticking their hand out for access on CRP land. It drove up the increase in fee hunting big time and ruined access for a ton of average folks whose tax...