DR
Man, how can you expect experience from anyone of us here on such a weird shape building?
That aside, here my two cents:
I'd go with fin-tube all the way, no UH's with fans, no moving parts, you can get the heat anywhere you want.
I imagine a HWS/R headers at floor level with a series of "U" tubes branching off teh header, finned the entire height (or intermitently) along the walls, similar to the Whalen systen without the fan coils.
Or, radiators similar to the Runtal radiator system in lieu of FTR's.
I'd add a snow melting system (electric?)on that roof (or more fin-tubes immediately under the roof) to make sure the racks will not collapse from snow load.
For Ventilation, I'd use a supply fan at low level and relief damper/hood on the roof (high on the walls)- Keep the fan in accessible place.
good luck though