I have a Jackson Coosa (the original, not the HD). Yes I fish the skuke for trout (above Auburn reservoir) and bass (from Auburn to Hamburg typically). Did Tionesta Creek last weekend. Did the Pine through the upper gorge this spring. Swatara up around Pine Grove. Have done the Clarion. Been wanting to hit the Little J through the gorge, as well as Penns from Poe down to Cherry Run from a yak but haven't got to them yet. That's the size of water I like to target personally, though yes, I've done big water like the Susquehanna and lower Juniata as well.
Sit on tops are much superior to sit in's for fishing generally. The seat is important for comfort, typically the separate chairs you put on are much more comfortable than anything molded in, and have the added advantage of having high positions for fishing and low positions for running rapids. Pedals are useless on smaller water unless they go completely within the hull. In summer in riffles you will be scraping a lot, even getting out and dragging on occasion, and even a flap that folds up against the body will come off and be gone forever, as a buddy with a Hobie found out. Not an issue if you stay in the same pool like Afish, but if you are running distances through riffles it is. A trolling motor is a good idea if you can use it only when you want it. Put it on for lakes or big rivers, leave it off if running smaller rivers and creeks as it lowers your draft just from weight alone. Draft is important. I want to float freely in about 2" of water. Any more and you will hang up on every riff and even in many flats. At 2", you're still hitting rocks, but when you hang up on a rock you can typically lunge forward by shifting your weight and not have to actually get out and drag. Most of the time. Even if you have to get out and drag, it's usually only a few feet, just to get over a lip. If it needed just 1 inch more draft, a few feet turns into a 30 yards real quick. So I pay attention to keeping my gear light too for that reason.
You will get dumped on occasion. Don't worry about it too much. Almost always it'll be in shallow/fastish water due to hitting a rock sideways, or swept into the shore. It's almost refreshing and you just laugh and jump back in the boat. Just make sure you have everything tied down. But I tend to avoid moving water in winter when the water is cold.
As far as stability, my boat is 33" wide I think. It's standable for me, I'm 5'8"ish and 185 lbs. But it's not real comfortable to actually fish while standing. A wider boat or a shorter lighter person changes things, so you gotta figure out whats right for you. Anchors are doable, and a drift chain works well too, I think a little better for moving water (the Jackson's come with a chain chute). Never use either in truly fast water for safety reasons, but in a moderate current the chain will slow you waaaayyyy down and keep the boat oriented, in slow water it'll stop ya.
Longer boats are heavier and less maneuverable but paddle faster. Wider boats are heavier and slower, but more stable. Just trade-offs. Height leads to wind issues, which is hell on a lake or large river like the Susquehanna but not a big deal on smaller water. Weight is a huge issue if you are cartopping, or expecting to have to portage around dams. I'm 42 years old and fairly strong, and the Jackson is mid 60 lb range. That is as heavy a boat as I want to drag around portages or cartop. It's on the light side for a fishing yak, and as heavy as I wanna muscle around. Dragging it around a lengthy portage is a no go, I can drag 100 yards or so though. When the girl is with, she dreads carrying it (with 2 people!). On the other hand I got my kids and gf a 40ish lb cheapo Pelican. I can carry that distances alone and put it up on the car from the side!!! That 25 lb difference is amazing. I take it off the car, balance it on my head and hike to the stream, and toss it in. When alone I take it sometimes. It's not as stable and the seat sucks for an all day trip though.
