Concrete platform + steel framing isn't unusual for commercial or multi-family residential buildings, but it's pretty much nonexistent for single-family housing. If you want a concrete/steel house, you're better off going with insulated concrete forms (ICF). In cold regions, many basements are already built with ICFs so finding a contractor to build an entire house that way shouldn't be too difficult.
Don't sell wood short though--contractors can build crappy wood houses, but they can build crappy concrete houses too, and a good wood framed house loses nothing to concrete, except maybe sound insulation and resistance to damage. In your region, as long as you make your house airtight (through taped sheathing, liquid or taped membrane, or airtight drywall) and keep at least 33% of the insulation value outside of the sheathing you should be good.
Don't sell wood short though--contractors can build crappy wood houses, but they can build crappy concrete houses too, and a good wood framed house loses nothing to concrete, except maybe sound insulation and resistance to damage. In your region, as long as you make your house airtight (through taped sheathing, liquid or taped membrane, or airtight drywall) and keep at least 33% of the insulation value outside of the sheathing you should be good.