As you already pointed out I think LRO will be able to help you with all your fly fishing gear needs. You might want to give them a phone call before hand and see that they have your sizes and models your interested in. They will be able to give you some ideas of other equipment to think about before your visit.
One other good thing is if your staying in Gatlinburg and visiting LRO you will be driving right past the Elkmont area. This is where I would start. You could easily spend a week in this area.