I think you're on the right track, Niner. Hey, maybe your electrician buddy has a short length of #10 romex, or better, a couple of pieces of 10 AWG for the module to controller run.
Forum member Avion 69 is working on his solar system and used an enclosed irrigation control box to house his controller. That gives a user a lot of latitude as to where to locate the controller.
Reading between the lines and from the info you've posted, I'mm thinking your usage is on the lower sides of things (no kids, no microwaves for instant feeding, no hair dryers, no high-use heating, etc.). Your 120w panel should serve you pretty well. If, in the future, you decide that you need more charging, adding another module is probably the ticket. I'd suggest you plan for it when buying a controller or figure out how a second, smaller controller is going to be installed. The larger controllers seem to offer more features but a second, cheaper controller, may be more economically efficient.
Good luck on the upgrading!
