First, I don't own any of these, so these are just a couple I would look into if I were in your position. I'm assuming by lake/river paddling we are not talking whitewater or tidal races, but flatwater rivers.
If you're a smaller built person, the Impex Gale or Impex Mystic, both 14' X 21 1/2" x 11" depth, should get you towards nice typical all-around sea kayak performance. The Walrus Griffin 13'11" x 21.75" x 11.75" depth and Eddlyline Samba 13'10" x 22 1/2" x 12.5" depth you could try if you're a little thicker in the thighs and seat. While there aren't that many out there at 14' that look like they would give nice performance, when you dig, there are a few that stick out to me.
Others I personally would be less initially attracted to, largely because they get beamier, but still I think I could end up enjoying, would be the Necky Looksha 14 or Manitou 14, Dagger Alchemy (I understand this one is quite squirrely compared to typical desired performance outside of rough water play? I would probably enjoy this one in the surf, but that doesn't sound like it's your current deal?), Current Designs Vision 140, Seaward Compass 140, Seda Vida.
Maybe someone skilled has experience with this 14' range and can give impressions, but I'm guessing those first 4 may offer a bit sportier fit, feel, and performance, for typical performance oriented kayaking, the Alchemy leaning largely towards playful rougher water performance, and the rest the step between recreational and performance kayaking.
Don't you wish you could have them all at a single shop on the water, ready for you to demo? I think I'd want to join you just to get a feel for what the 14' range has to offer.
Deck Rigging Gear
Recreational Kayak Paddle
Full Size Sail Rig
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