Be careful when using "unvented" heaters... I.E. No outside chimney.
I would encouage using a carbon monixide (CO) detector, as well as doing some experimenting outside or in the garage (you don't want soot buildup in the house).
As I understand it, there are two methods for feeding.
Capiliary / Wick.
Pressure / Gravity.
If you look at many of the liquid fueled camp stoves (including multi-fuel stoves), most of them use a pressurized tank (same effect could be created with gravity feed). They also have a pre-heater as part of the vaporizer.
Hmmm...
Another thought,
Many LP/NG heaters (and some white gas heaters) also use a non flaming catalyst type burner.
You could experiment with a coleman-style white gas camp heater. I believe that you turn them upside-down to prime, then light, and they are supposed to briefly flame up, then lower with a catalytic heating flame.
