Steve,
Have a great time! We have been to Hilton Head and Branson many times. Both great and completely different. Both are off season right now. The weather will be cool but the crowds will be less. Still, in Branson, get a map and drive the "alternate routes." You DO NOT want to get caught on the "strip" any more than you have to.
In Branson, I would suggest Danna's Barbeque and Tony Z's. Danna's - very casual and Tony Z's is fine dining. You will throughly enjoy them both.
Have fun!
Mark