Recommended Solar control module for 50W solar panel?

Thanks everyone. I just ordered up the Sunsaver 6 for my 50 w panel. not sure but I think I could add another 50w to it later? since they are less than 3 w and the panel goes to 6? But, If not, it was inexpensive, so If / when I want to upgrade later, no biggie if I need to upgrade it too. Thanks for all of the help. I think this will work well for me for now, I don't do a lot of off grid stuff as of now anyway. This will basically just keep my batteries topped while no shore power is available.

Thanks