the 1950 is a nice unit. But.....If it is bought w/o a blower then it must be installed in series with the current furnace. Which isn't possible with that setup that he has. Plus price, the least I saw the 1950 for was 2000. If I could have gotten the financing with the interest I wanted, I would have had it. Ideally you don't want to use the central furnaces blower if possible. When the heat from the woodfurnace enters the plenum of the main furnace, its hot. Now kick on that central furnace blower and it will temper the air, to where you will luke warm air at best. Now get the cfms in the larger ducting, get a return on the system and install a damper in the plenum of the main furnace. With enough flow from a large blower on the wood unit, you get enough pressure to force that heat through the ducting w/o the central furnaces fan. Therefore only wood warm heat. With the 1600 you can choose 1100,1250, or 1400 cfms of air through the blowers. You wouldn't have to modify the furnace in any way. You could possibly heat with the other, but it would need to be modified quite a bit. Like I said before though, Return air with the woodfurnace is key. You want that clean 70 something degree air from the house to circulate the firebox, not the cool air of the garage. Plus its not a bad thing to go one step larger, especially on those below zero nights. You'll appreciate it.