That boat looks to be very much like the 3m boats I used to use for whitewater back in the mid to late 70’s Heck if yours was green it may have been my old one.
It’s a great design but made for downriver, and downriver salaam. And being fiberglass, you can easily grind them down and repair them, without too much difficulty.
If you’re looking for River in a tidal zone, and not whitewater. I’m quite happy with my Wilderness Systems Tsunami. I have the 17.5 ft one, and I get nominally with a Whitewater High Angle paddle, about 4.9 to 5.5 Mph. The Primary and Secondary stability is well rock steady Si much so that I’ve been doing Dry Entries off a dock with a 2-2.5 ft step-down into the cockpit.
The boat is FAST, and STABLE, but does not under any circumstances turn on a dime. The best I can manage to do with rudder and edging (And yes you can edge right to the cockpit rim) is a turn in about 3-4 lengths of the boat wide.
It also carries about 400lbs of you plus cargo.
the cockpit has plenty of room (I’m 6’4, 246lbs.) so it fits my big feet, and fat ass pretty well with sufficient leg room for me to get in and out easily.
if 17.5 is not you thing they do come in sizes from 12 ft, through 17.5 ft in about 2 ft increments. Though only the 16 and 17.5 are rudder equipped the rest are all rudder ready.