|St Louis to Dallas in August? Sounds about as much fun as riding across the surface of the sun.
Only advice I can offer is: Missouri and Arkansas both have great twisty back roads. I'd stay off the superslab if I was you. The Dallas metro area is a nightmare of suburban sprawl from what I remember. Never been to Southern Oklahoma, so I don't know what it's like (though I think there are some low mountains there - the Ouachitas maybe?) I've been through Oklahoma multiple times (Mom was born and raised in Northeastern OK and we had relatives there for years) but never south of I-40.
Englewood, CO (Denver suburb)
UJM (Universal Japanese Motorcycle) Fanatic
Previous Bikes: '69 Honda CL450; '74 Honda CB750; '83 Honda 550 Nighthawk; '92 Yamaha Virago 1100; '83 Yamaha Maxim 750; '84 Kawasaki ZN700 LTD; '01 Triumph Thunderbird 900; '82 Kawasaki Spectre 750