Just be aware re zoning that if you balance the system for the whole home and get it working well...THEN...insert manifolds etc to slow / block airflow then you may get some issues with over / under airflows in the rooms you utilise.
The only advice I can offer having spent 10 months of hell working with a well known firm who were Fujitsu trained is make sure they have installed and worked on many many many ducted systems as they are an artform and law unto themselves :) It's a fair bit more complex than running copper pipes and filling with refrigerant as both I and my installers eventually figured out.
I would also consider installing the vents ( they fixed 70% of our issues ) where there is an internal metal coil that opens or closes the vents based on cold or hot air flowing through them. So hot air is fired downwards to the floor then rises up to warm the room and cold air is fired out at ceiling level and drops down to cool the room. Without them we found we had a very very hot roof and hot heads and freezing feet and bodies. I remember the $40 day of electricity we used as the outdoor unit sounded like it was trying to take off with the temp at the controller registering about 13/14 c.
If you are in CChurch then I can give you a contact at Gavin Lowe ( they weren't the company who installed the system but I wish they were ) who eventually came out and sorted the install issues as well as balanced and brought the system upto useable and enjoyable. English lad, about 20+ years of experience and knew these things inside out and back to front.
Best of luck and post back as to how you go
Ged