SOT or SIK
I just recently bought a Wilderness Systems Victory Bravo SIK kayak. It is 9' long and only weighs 45 lbs (I think I've eaten things that weigh more than that!). I'm learning how to paddle, but so far, I've discovered that these things are FAST and smooth compared to almost anything else I fished out of. It's nothing to cover several miles in one of these. I've even started just exploring (without fishing...there's a change!) with it and I may do some whitewater later after I've learned the strokes and such (I live near the Ocoee River...whitewater heaven....). I've had no trouble fishing out of it what-so-ever, and it's way superior to my old Belly-Boat.
I am 47 years old, 5' 7" at 225 lbs. I have a steel rod in my leg where my thighbone used to be, and a re-constructed hip-joint. I haven't had any problems using the Yak, although I've made a few adjustments to getting in and out techniques. I put my Yak about half-way in the water at a 45 degree angle to the shore, then sit down on the ground next to it. Then, I use my paddle to lever myself in the cockpit by placing it behind my back, straddling the hull just behind the cockpit with 1/3 of the length, and the rest on the shore for support. I just lift myself up with my arms, using the paddle as a crossbar, and swing my feet and butt into the cockpit. Then, all I have to do is a quick forward Hip-Snap, or maybe 2, and I'm floating and on my way. Getting out is just the opposite....EASY! I'm sure you could do it.
I like my SIK, but I think I may get a SOT later just to explore in. I think I'd also like to buy a Touring Yak next year...the wife permitting.