Re: Thinking of getting a Jon boat w/ a jet...
I would recommend a jet to anyone fishing the susqy.. Just because you can, doesn't mean you have to, but it's an added piece of mind. You don't have to run 4" of water on plane, but the susqy isn't like most rivers with gravel bottoms and shoals that you're running, it's full of boat busters that don't always show themselves. Anyone that has run the river much has had plenty of instances where they look down and realize how close they just came to a boulder..
It takes a while to get used to operating a jet, and even longer until you feel comfortable. You start to learn to read the water and running skinny water becomes much easier. Having said that, the time you become complacent and think you know the water is when you'll hit something. Having a fear for the river is healthy, it takes way too many people.
As far as the boat.. I haven't personally had experience in a 14' jet with a 25. I'm assuming it's a 48" bottom being a grizzly which is fine for a jet. The thing with jets is you can't just change the pitch to get better performance, what you get is what you get. You're going to run the same rpms whether you're plowing water or up on plane, and you'll be pushing the same amount of water through the motor, but the load in the boat can affect the boat severely. Not sure what the hull is rated for (probably 25), but I would definitely max the hp with a jet (the amount re-rated for the pump). Because you'd lose 30% of power you're 25 is more like an 18. It would probably be fine if you're by yourself, but start loading it up with 2 guys and gear and getting on plane may be tough. If you check outboardjets.com you'll get a ton of info. The bigger the motor the less drop in performance you'll have. My 17' with a 90/65 does 35 when I'm by myself, but duck hunting with the blind on, decoys, 2 guys, guns, gear, etc, I'll see low 30's (these are all GPS'd). Jets are a completely different animal than props, and there is a ton of info out there. Definitely educate yourself as best you can.