radiant heat panels will be enought to heat up the enclosure. dont bother with a misting system. in my opinion they are pieces of trash and misting youreself doesnt take too long. if you house gtps in plastic enclosures and mist daily then you'll be fine for humidity. a snake hook is a good investment. and if youre going with a baby gtp then grow it up in a 10 gal or small rubbermaid first. have it feel secure and reduce stress and he'll do much better. many ppl use 24'x24'x24' for adult gtps but greg maxwell(the gtp master) suggests 36'x24'x24' for bigger females although he does say the smaller ones can be used for smaller males. and im gonna have to agree with him.
just do your research and set up your researched enclosure before you bring the little guy home!
good luck!