who has a good floor system. My historic building will only have floor to ceiling heights of 8'8". I need to run high efficiency HVAC air ducts, lighting wiring, etc... Which company offers the best flooring system to complement the walls?

Your question as presented probably cannot be answered. I suggest you have your designer or archie evaluate the systems out there, to see how they could work for you. I base this on your comment about 8'8" between floors, but you don't say how thick you can build the floor platform(s).

McRockFish,

Once again Jim is right more information is needed. If depth of the floor is a concern then a precast floor may be in order for they are 6 to 8 inches thick. Dending on your spans wood I-joist, steel I-joist with concrete slab, and cast in place concrete slabs all use 10 to 18 inches of space.

ICF Contractor

I did notice the high efficiency ductwork comment, and wonder also which system is planned at this stage?

The inclusion of a high-velocity system may solve the cooling issue, and you could use a hot water based heating system, which may be a little more "authentic"?

Gee, what was used for heating in old historic(or repro) buildings?

As Jim said many factors should be considered. However I can recommend you to see also the "Prescriptive Method for Connecting Cold-Formed Steel Framing to Insulating Concrete Form Walls in Residential Construction"

Prepared by: Building Works, Inc., Cambridge, MA, Contract H-21311CA,
February 2003.

May it helps as an idea.