Flashlights (many of them!)
Paper towel/Toilet Paper
Walkie-Talkies (for you and your wife when you go to Walmart and lose each other)
A good multitool (Leatherman)
Burgers, Sausages, Chicken and steaks
Might as well buy a portable BBQ with all that meat
GPS (so you don't learn a damn thing about anywhere!)
Batteries (AA, AAA, 9V) you need the 9V for your smoke detector and multimeter
Oh yeah! Multimeter
Gloves for handling the pooper pipe and valves.
Hand sanitizers (we buy tiny travel ones and hang them off every corner including one right at the sewer valves)
Clear (seethru) sewer neck to observe the beauty inside your holding tanks leaving the premises in an acceptable fashion.
Tequila (to cope with the pain of seeing your money vanish at staggering rates)