Loft Apartment HVAC

JAGS Resto

I am about 6 months away from decision time on HVAC for an 80 year old 2 story brick building I am converting to (2) Loft Apartments.
The walls will be bare brick with 1 wall covered with original plaster.
The ceilings are 11 feet original Tin ceilings which we have insulated(blown in)
The windows have not been replaced as of yet but we will be going with a high effeciency window. The floor space is just under 1500 sf each with an open floor plan except for one room (approx. 200 sf.). We plan on exposing the duct.
Any PERLS, words of wisdom, suggestions, with this non-traditional construction?
Insulated duct?
BTW, the location is in North Central Texas and it does get HOT and Cold.

JAGS Resto