Why not just go camping and make a list of items you want to take next time. What one person needs is not necessarily what another needs.
By the way, how much propane you use will be determined by how much you'll be using it.
Also, how long before you have to empty the grey and black water tanks will also depend on how quickly you use them.
Finally, how often you have to go to the grocery store will depend on how much food you bring and how much you east (this will also help you determine the need to empty the tanks.
Hope that helps and saves you future e-mails.
