We run kif in our Terpenators, but short of that, the best way of extracting kif that I've found, is with 190 proof ethanol. By starting with kif, virtually all of the unwanted pickup issues are eliminated and it produces a delightfully floral, pristine extraction, which I prefer to a butane extraction for all of the subtle undertones.
Iso will do the same thing, and is faster, but is more robust in flavor itself and doesn't produce quite as suble undertones as ethanol.
No need to freeze, just mix the two together and periodically shake until the resin is dissolved, before filtering and evaporating away the alcohol. We use the same general procedures in QWET extraction, except for the temperature and time, so you might check it out for evaporation and purging.
http://skunkpharmresearch.com/qwet-extraction/
For an E-cig cartomizer, we use a 510 cart without poly fill for shatter and with the polyfill wick in tact, for decarboxylated oil. Either works well on a generic battery pack, and the whole setup was under $30. More details at
http://skunkpharmresearch.com/portable-pen-vaporizers/