Floorless shelter and wood stove would be my recommendation if you want heat. I personally wouldn't use a gas heater in a tent, but that's me.
If it's the cold air that bother you, why not wear a backlava (?spelling?) or neck gator over your mouth. I wear one when out and about when the temps get to about 20 below and it helps alot.
I'd also say buy a quality sleeping bag rated to at least ZERO since your from Texas and you're not used to the lower temps. That will help.
Just my 2 cents.
Mike.
