The first thing you need to assess is how much power you use. Any recommendations will be skewed either too much or too little because of that unknown.
Link to a spreadsheet calculator.
FWIW, I have a single 235W module and 300AH of battery capacity. I run a 120V fridge, 120V entertainment gear, and all of the 12 V stuff without an issue. I do have a tilt mechanism that I use when in storage.
Your side mount system will serve the same purpose and also act as an awning when deployed. There are a couple of members here that use that side wall mounting system and you can make it detachable for more functionality.