There are excellent covers or Ode to Billy Joe out there, it is worth spending time seeking them out.
Danny Gatton, some strings and horn arrangements and the like. If I hadn't wasted enough time already I would seek out a Cuban arrangement or something that takes that rhythm further out. Is it 6/8 sort of bossa? (I don't know making stuff up here)
As for Convoy, the movie is worth watching just for the cinematic cliches and the Kristofferson. Musical covers, I doubt there are good ones.