So, for just running one thing at a time the cheap one is fine? But more demand will cause freeze up.It's al about preventing frost..
The biggest thing I do is heat water, and that is quite a flame, but do not usually do much else - maybe cook on the stove at the same time, or possibly run the heater in cold weather. I think the fridge is insignificant.
What I need is best solved with the style of BBQ ones, the RV store has configurations that complicate things.
Yes, big vent, little vent. The BBQ ones just have the little vent (tiny hole)