Wiley Post, KPWA, would probably be most convenient for you (since 2DT closed and has been turned into a concert venue). It's very close to the Northwest Expressway, which will give you good access to anything else you want to visit. There's lots of activity there, including several warbirds. Sundance, KHSD, is several miles further out of town (to the point that you might have trouble getting a cab), and Norman--though right off of I-35--will be further away, and traffic can be a mess getting through the I-240 and I-40 interchanges. David Jay Perry, 1K4, is in Goldsby, several miles south of Norman, and is KOUN's equivalent to Sundance/Wiley Post. I don't know about the car rental situation at KPWA, but one of the local dealers has an arrangement to provide rentals at KOUN, and I believe will meet you at the terminal. Call the FBO for details.
KPWA and KOUN both have restaurants in the terminal; I like Westheimer's restaurant, Ozzie's, better (and they have all-you-can-eat catfish on Friday nights). I haven't been to KPWA's Annie Okie's Runway Cafe in years. Ponca City has a good Mexican place called Enrique's, but coming from Alabama, it's not exactly on your way (though at RV speeds, it's not that much of a detour); if you do that, call and get their hours first, as they close at odd times (ask me how I know!).
Does that help? Anything else I can answer?
Edited to add: there's an OU football game at home on Saturday at 1100 local, so expect road traffic to be an unholy mess all day, save for the time actually during the game. If you plan to arrive Saturday, don't even think about Westheimer. You'll regret it if you do.