So, sh*t's expensive right now. $1100 for a Reznor 30k, $770 for a Sterling 30k, $860 for a Modine 30k.
I opted for the Modine. Now I have hanger mount vibration isolators, unistrut, 3/8 all thread and hardware, tstat and wiring, horizontal stainless venting and this 66lb chunk of natural gas...