These guys are spot on about good tires, a spare and checking air pressure. The jack in the 2500 Chev should work if needed. Having replaced all 4 tires over the last 3 summers the only other thing I can think of is a big hammer or something to pound a destroyed fender back into place (and avoid the tow truck joys) should you have a nasty blow out with collateral damage. When a rear tire blows it likes the buckle the fender right in towards it. Ask me how I know...

And maybe a few helpers to share in driving or flat changing. It's a lot more fun on the side of a busy freeway when it's 95 degrees out.