your problem is you think heat is the only form of energy/power
get some physics books
and the reason an led uses a diode/resistor is to limit the current...else you will burn up your led
Watts is POWER
It does not necessarily transfer to heat.
You could look at an infra red ceramic as an extremely inefficient light source where most of the wattage transfers to heat.
Plastic container
Fill half way with rolled oats
Put an egg crate on top
Now you have a place to put gutloading
Though it could be more economical to separate some for loading
http://www.amazon.com/Zoo-Med-Reptisun-Terrarium-Hood/dp/B00LQKAKEO/ref=pd_sim_sbs_199_3?ie=UTF8&dpID=51iNzS1djtL&dpSrc=sims&preST=_AC_UL320_SR320%2C320_&refRID=1651SHSKZMRGDPAXA3F0
It's a protean
http://www.customglassterrariums.com