Ah, southeast river; let me also suggest then the boatertalk forum. They may be able to give you an idea of how those boats might perform on your particular stretch of river.
Neither of those boats are designed for whitewater. You will see that they have pointy bows that help you track well in flat water, but will be significantly harder to "turn on a dime" than a whitewater boat (as you might have to do in a shallow rocky river). If you are talking about a narrow river where you will swim to shore (vs. a self-rescue involving climbing back into your boat on a big lake), the deck lines I mentioned earlier are not an issue -- whitewater boats don't have deck lines. Assuming you won't be rolling, you just need to be able to hold onto the boat as you swim to shore (not necessarily fun if the water is fast and the rocky bottom is close) -- deck lines would help a little for that, but are not crucial.
You might actually consider a whitewater boat since you mentioned class II - III rapids (like I said neither of the boats you mentioned are whitewater boats). What you give up with a whitewater boat is flatwater speed and tracking -- I don't know if the river segment you speak of has a lot of flat, slow sections.
If you don't know, there are a few boats that are designed to be crossovers, that is, they are not dedicated whitewater boats, but they have hull designs that will turn easily -- many of them have skegs that you can drop when you want better tracking. I have not kept up on all the options there, but I know of the Liquid Logic XP 9 or 10 (size difference) and the Pyranha Fusion (I know there are a few more -- searching crossover kayak will turn them up i bet).
I really don't recommend a boat with a cockpit opening so large that you can't get a skirt to fit. The skirt will keep you dry in the rain and waves and if you tip a bit -- also keep your boat from filling with water and swamping. If the river and air temps are warm, this might not matter -- if so, there is the "sit-on-top" kayak option, too.
Even another option, depending on the river, is an inflatable kayak like an AIRE Tributary Tom Cat, great value, even more so if you get a used one (Leisure Sports or Rendezvous River Sports might be getting rid of their rentals, or maybe they did already).
So many boats! So many rivers! Good luck.