NC, It depends on how deep his pockets are....
You will NEVER stop the *****ing and moaning from the tenants.
I have a couple of these (accounting office who rents to realtors, investment people etc.).
We have done this with a simple zoning system as stated above, with a central hall return (if possible) You can do crossovers to the hall if necessary. You will have to look hard at the duct work and probably have a "dump" zone. "Most of the time" zoning will help the capacity problem because some people will be hot/cold natured and need less airflow.
P.S. I really like the "auto correction" feature of this site!
I did not know it was there.