I had a 100w Renogy panel hanging off the back of my boat for the past few years in Chicago. I took a bimini bow, cut it in half, picked up some hardware to mount it to the stern rail. The panel height was adjustable and stood around the same height as the bimini. This allowed for good visibility.
The 100w panel was overkill. I would buy a 50w next time. I had a pair of Morningstar SunSaver 6 controllers. They worked well. My main battery was eight years old when I sold the boat. The only downside to this model was I couldn't tell how full the batteries were but that wasn't much of an issue