Your subject line does not really fit your question. Hitzer makes a fine stove, if it works for your application. The answer to your question of whether a fireplace insert will work in your situation is an emphatic NO
A fireplace insert is assuming that there is a brick or other ceramic installation already in place and the insert would slide into that. While I am not sure of the exact heat that is generated, you can say that it would be substantially more than combustibles would be able to handle. This is why most stoves (not inserts) are still required to be several inches away from combustible surfaces.