If you already have loose blown in insulation above the ceiling, it might be a messy proposition installing ducts. You could run an exposed duct with individual registers, but that interior is sooo nice, Id hate to screw up the look. Another alternative is to hang individual heater units, but again you lose the clean look and ability for combo heat and air.
If you look at my avatar, I created a false soffit (where the clock is) and put all the hvac ducts, water, air, electric, and low voltage lines in it. If you look at the far end, above the flag, you can see the large center hvac return. All the feed and return ductwork connects to a combo oil furnace / AC unit in the next room. Ill see if I can find some pics of the unit.