I have recieved great help here (especially from Irascible) and where I find help I always try to give back.
This may not be new information but it is all I have to offer .. so here goes.
I have a 2670 foot 2 story in So Cal with just one shared zone. It has a large 22 flat ceiling over the living room and an upstairs balcony. My house had huge classic needs 2 seperate Zones, one upstairs and one downstairs as well as a large dead space all across that 20 foot ceiling. The only possible place to add vents would be the inaccessible attic.
At the edge of the balcony I mounting a large external variable speed vertical blower 12" below the ceiling sheetrock and a variable speed controler in a standard hieght on the wall. The blower is mounted right between the downstairs cold air return and the tsat (which is downstairs). I leave the VS blower set to half speed 7X24. Because the blower has large fan blades operation is silent and draft is not objectionalbe but the downward throw is strong enough to cycle air off the ceiling into the cold air return and better stablizes the temp at the tsat reducing short cycles which leads to better, more even heating and cooling effectiveness. The blower only cost me $150 and has proved reliable. I know that running the blower has reduced furnace time and cycles and so must be saving money. Some people might think a large externally mounted blower would to be too unattracive to mount in plain view in the living room. However, most people who notice it say they really like the look of this Casablanca ceiling fan and think it was a great idea to install it.
I have never heard a HVAC contractor offer a ceiling FAN as part of an overall system solution so I wanted to suggest it to the contractors here provide help as a way to potentially increase sales revenue. It seems like you would only need to carry a couple of basic reliable models in stock, could differentiate your bids and make a little more money.
Just sharing an idea. Hope someone finds it helpful.
Thank you to all those here who provide help to others.