Johnson County is listed with a varying bedrock depth of 10-20". That's a component of a larger survey, but that may be one to factor in on foundation costs. Hard to say, but if rock is involved and a known obstacle, it can add a tremendous amount to a bid.
If the footing excavation includes rock clause verbiage, I'd suggest finding a contractor whose known to work in that specific area.
Lifts or any point loads are typically anchored to a spread footing or pier. The entire floor doesn't need to be capable of supporting point loads, only the attachment points.
On cost, without one manual shovels worth of excavation, the floor, locally, would breakdown to around:
$7.16 PSF with #4 2' OCEW, 4000 psi, visqueen, formed and finished.
$36 PLF for 12"x36" footing with (12) #5s, corner bars, hairpins (as required)
Again, no excavation is included in these figures and based on a local cost of $93 per yard (delivered with tax).
Betting the site work is a huge component of the estimate, which can be expensive, especially if adjoining residential properties, based on the grade you described.
That said, the total expense is ~$21 PSF and that's almost 1/5th the national average of finished new home construction.
I guess I will deal with this later - - either that or go with a 32x28 
