I have just completed building a 24x26 metal building with 9' sides on a slab. I want to use 4x8 paneling for the walls and ceiling but am not sure if I should install studs between the 2.25" metal wall beams or if I should use 1x4s for furring and attach the paneling to that. Does anyone have any ideas. Also does anyone know how much cheaper it is to use rolled insulation vs. having foam sprayed on?