I built my Temp-cast heater 14 years ago, works great! Yes dry stacking is a good idea. I have see a couple built by professional masons who thought they knew what they were doing and made mistakes. Dead easy to build if you follow the instructions.
I would appreciate if you could provide the throat opening dimension (as it enters the black oven). Also, what is the recommended chimney cross section area?
I bet that someone from China has this kit too right now...and they will make some updates or small modifiers to it.. and call it their own :) Then ship it back to USA on a smaller price.