I can't be too specific about your need, but I had a 1 ton unit installed by a reputable dealer in my shop. It cost a bit over $4000. I have seen do it yourself units with a charged, sealed, fix length tubes for less than a $1000. I figured getting a brand that the HVAC company would stand behind was worth double that now double it again for complete install where I wanted it instead of X number of feet away max, was worth the professional install. Took two guys about a day. They actually gave me a free estimate with an un-site evaluation of my needs. He said if I wanted heat faster I should go with a 2 ton unit for about $1000 more. I plan to leave it on all the time and it did take awhile to stabilize the temperature. The outside unit is nearly silent on this unit. I have to be standing right beside it to hear it. Inside is even less noisy. I have only had it for a couple of months so I can't evaluate completely, but with it running almost continuous the first month to equalize a lot of masonry and steel, I figure it cost me about $1.50 a day to run. should be cheaper now that it has everything up to temperature. Haven't needed the AC part yet, but having my shop at a steady 68 is nice. I had it at 70 but decided that was too warm for a work space. Several friends have them in their houses and as long as you have an open enough floor plan to move the air around they work great. Also good down to around zero where regular heat pumps give up around 20 degrees or so. If it is your sole source of heat you may want to go bigger than you think you need, since they do put out less heat at very cold temperatures. For my shop I didn't care if it got cooler in extreme conditions. My neighbor runs a small wood stove when it gets real cold.
I just re-read your note, mine was for a single inside head. They mentioned they also had units for limited duct work, I didn't need that but it sounded like it would not handle big duct runs.
