Where to begin, hopefully your water heater, furnace and sump pump are all close together that way you can frame 1 room around all of them and mame that a mechanical room. There is no such thing as a floated concreat slab, as it is not a part of the foundation, it is poured after the walls and right on top of dirt. I don't like the idea of hardwood on a concrete slab because if the concrete heaves at all your hosed, I would just do carpet everywhere except the mech. room. I did a drop tile ceiling so that way you still have access to everything that is up there, it look good and is not that much more than drywall. I hope some of this helps, I just did mine and love it( the basement) I framed houses for 10 years and did it all myself. If your not far from me I could come over a give you some pointers.