Solar Panel Layout?

I'd suggest you figure out what is going to be the most robust layout for your wiring and modules, now, and install it. If that includes a fixture for auxiliary modules, I'd do it now and be done with it. Also, don't get sticker shock with using larger wire sizes. It's much better to have a little too much than spending good money for the modules and controller and losing power to a small wire.

The Anderson connector the Wynns used is a good connector. Mighty handy to run other DC devices outside besides a charge point connection.