Ducted mini split capability

Hi ,I am wondering if I can install a ducted mini split unit below the floor in each first floor room in my old Victorian home. I have an old gravity fed hot water radiator system with a bell and gosset pump that works fine for heat. I would like to zone each first floor room separately, Kitchen ,Living Room ,Dining room, and Family room .Is there enough volume to blow the air up through floor vents for it to cool properly ,is there a limit to how many ducts ,duct size ,and length for each indoor cassette .Am I better off with one large supply and return per room. I plan on having ducted mini split units in each of the 4 bedrooms on the second floor above the ceiling in the attic separately also. Or is there a better way with space pack, or ? Its a big house and I hate to air condition every room. Its only my wife and myself. I would want it to be sufficient for someone with a family if we ever move. I thought maybe with the heat pumps in the units we could heat certain rooms also in the spring and fall without running the boiler we live in Riverside IL.Thanks