That Hyfire is going to do real well. With the hot air jacket around that large radiant area on the sides and the hot air vents off the top, you will be getting a lot of heat. If you hook up the cold air return to the blower inlets from the other end of the house, I think you will be amazed at the even temps and temperatures.
Can you get a cold air return upstairs as well?? Now that would make a HUGE difference. Maybe on the underside of one of the back stairways?