If you're talking about on-road, Eureka is a good hub - there is so much great riding proximate - particularly if you want to venture into southern Missouri. I generally shoot up from Sherman to the Talimena drive then over. You can go straight up75/69 to Stringtown, then over on 43, which is the fastest, but a bit boring. I prefer to cut over on 70 out of Durant, then north to Antlers and take either 271 or 2 into Talihina, then make your way into Mena. If you have a week, you can call it an easy day and overnight in Mena, or overnight in Fort Smith if you want to make more progress, then move on to Eureka. For a longer day, push on to Eureka Springs (about 375 miles from Sherman via this route). There are also quicker, less enjoyable routes to Eureka that save time. With an early start, it's not a bad day into Eureka. If you stop in Fort Smith or in Mena, there are some great windy routes into Eureka, but those are too much to try to tackle on the way up, plus you're getting later into the evening, tired from the ride, etc...
Hot Springs is also a good launch point for an overnight, then up to Eureka. A fresh start out of Hot Springs, lets you run up 7 to Ola & Dardenelle through Russellville then take your pick of great roads throughteh Ozark St-Francis forest to Jasper, Harrison, etc. Harrison is a decent hub as well, but Eureka is a cool town to stay in.
I'm no help on the dual sport side, but know there is a lot out of the Queen Wilhelmina Inn area.