My advice is usually different from most. If you can drive to buy it at Wal-Mart, it is not a problem. I suggest.
+ A good 5 gallon gas can, filled.
+ A full sized TV spare tire (no donut) and make sure the storage release system is not rusted shut.
+ The knowledge and ability to change the TV tire.
+ A small 120 volt air compressor to keep the TT tires up.
+ A spare TT tire.
+ The tools, knowledge and ability to change the TT tire.
These are the things we took and used last year on a 6 week trip to MT. They were the difference between an annoying 30 minute delay and the DW and I being that old couple stranded on the road waiting to road service to find them.
Finally, keep you road service number handy, you cannot fix everything.
