All 3 boats you listed are decent options. Best if you can get some time paddling each to make your decision.
Note - the Zephyr comes in 2 sizes, and you more likely based on your size you would want the 160. The Stratos also comes in 2 sizes, but you likely could fit either, but the L may be better.
I don’t know the Ozarks, so not sure what the rivers are like. But you mention creeks, which leads me to believe narrower waterways. With that, you may find the shorter Stratos (14.5’) easier to turn than the other two (16’ and almost 17’). I have a Stratos L, and it turns on a dime as compared to when I am in a 17’ boat.
On longer boats that can maneuver, you are looking for boats that have a lot of rocker (bow and stern sticking up). More rocker usually reduces speed and ability to track straight. If you really want long and lots of rocker, see if you can find a Sterling Reflection. It is what I would buy if I won Lotto (you could buy 1 each of all the other boats listed for the price of a new Reflection). http://www.sterlingskayak.com/reflection1.html
One thing to keep in mind is the self-rescue requirements for sea kayaks over the sit on top you’ve been using. It may be good to take one of the day long intro to see kayak classes available at outfitters. Better yet if you can arrange for the class to use one of the bats you are considering, as this would also then be demo time along with education time.