Metal Buildings, best company to use, also wood construction ?s

I would rather put in a 4 post lift for more safety and I see it is possible to move it around, though once I get it where I would want it, it would stay put.

How do you insulate the pad? I know about putting plastic down first for moisture but not how to insulate it.

As far as insulating a roof, is foam board (stuff avail at HD/Lowes) is that good enough or is there better stuff to use?

For stick building, can you place a product like cinder block right on top of a concrete pad, to start the foundation or does it have to be "in the ground" like a trench? If you can put right on top, do you have to (or how do you) anchor it to the pad?