Alright, after much frustration, I have found that the Jotul 602 isn't approved for my installation due to ceiling height constraints. However, I have found that the Englander 17-VL fits. Just barely. It requires 11" on each side and is 20.375" wide. This brings the required minimum width to 42.375". The spot I want to put it in is 43" wide. I'm curious if I should be ok leaving the (what I assume to be) 1/2" regular drywall, or if I should install code X or C 1/2" drywall.
I've attached a picture to better portrait what is going on here.
I've attached a picture to better portrait what is going on here.