Solar hybrid set up

[Wrecit]

Blame it on my daily driver being a Prius but I want to do a hybrid power set up on my enclosed trailer conversion.

Been reading and studying solar set up for a few years but this will be my first practical application. I am going with a 2 panel 200w set up with a 200ah battery. I want to have a 110v battery charger built into the system so that I can use a generator to top off the battery as needed.

As I am understanding the theroy it can be done as long as I put an isolation switch on the panels and the battery charger. My question to verify is do I write the isolation on just the positives or should I fork out the money for a positive/negative shut off switch?