There are lots of diverse bits of geography in OK. All the places listed are unique. The temperature typically backs off around mid-September so outdoor activities are much more enjoyable. October is some of the best camping weather possible. If you have the time, I would suggest stopping somewhere in Arkansas on one of the legs of your trip. Petit Jean SP, Mt Magazine, or Devils Den SP are about as good as parks can get. Arkansas actually spends money on their state parks so the facilities are typically first rate. OK has some great parks geographically but they are not well funded. Enjoy the trip!