I'll also be heading back through Arkansas and Missouri.
Depending on your route and your beer preference. A couple you should look for:
Ozark Beer Co. Rogers, AR, small micro making some extremely good beer. The owner worked at Goose Island and is passionate about his craft.
http://ozarkbeercompany.com
Mother's Brewery Springfield, MO, growing brewery with some well received staples and some special releases that can be hit or miss. The current seasonal is a double IPA, Doozy. Very tasty citra hopped, I think it is awesome.
http://mothersbrewing.com
4 Hands St. Louis, MO, you can't miss this one.
http://4handsbrewery.com
Perennial Artisan Ales St. Louis, MO, another superb brewery that continues to be awarded for creative, delicious beer. It's just hard to get your hands on their limited stuff.
http://www.perennialbeer.com
Side Project St. Louis, MO, imagine Perennial on steroids. This was started by the Perennial brewmaster as a "side project". All of their beers are "rare".
http://www.sideprojectbrewing.com
3 Floyds Munster, IN you probably already know about this one.
You should be able to find Ozark Beer retail in the Rogers area but the taproom is a wonderful, laid back experience. Mother's is widely distributed in Missouri. Four Hands also has pretty good distribution but the tap room would be the best place to find a good selection. Perennial has limited distribution of their flagship beers but I highly suggest the tap rooms for them and Side Project. If you want 3 Floyds beer go to the taproom.
As mentioned above, research your route and look for others. There are many other gems to find along the way.