We use an inline cheapie filter, but bring either a 2 or 5 gal water cooler with us for coffee and water bottle refills.
A Progressive Ind. surge protector with indicator lights that plugs into the pedestal. I use this first to check polarity. Make sure breaker is off before plugging in. I also have a volt meter plugged in an outlet in the camper. One of these days I'll go full Monty with the interior mounted on Soundguy mentioned along with the PI converter.
Water regulator with gauge. I've run into a few places that warn you to use one as their pressure fluctuates.
Good luck and have fun.
Oh, also have a way to change a tire.