Talk to your builder about those options and see what he says. The guys who built my shop went ahead and installed the insulation and then they covered it with inner metal panels. Once the building was sealed up and insulated the electricians came in and ran conduit around the walls and hung outlets every 10 feet as well as installed all the lights.
I had PEX hose installed in the floor before the concrete was poured and then had a it hooked to a water heater. If you don't have gas you can use propane to fire the water heater. Can you trench over from the house for a water line?
