I am wondering about that insulation void you will have. Basically above the wires will be your indoor flooring which shouldn't need insulation aside from the rim joists. The spray from should meet where your XPS Rigid Foam is applied to the concrete wall. Then the gap in the ceiling, or soffit should be open for ventilation and hold your wires in place. Though fishing wires through that small area may prove to be no fun if you do not use something such as 2x2 tiles that can be removed for wiring. Maybe this project should be planned around any other basement renovation you want to do in the future, for example, how you plan on doing the ceiling in other rooms next to this closet?