Do you have much experience fishing and boating on that system? I grew up on the river right at the ND/SD boarder. The reason you don't see that type of boat on that system is because in the vast majority of cases, it's pretty impractical. The type of fishing is backtrolling, pulling cranks, or working a shoreline on the float (casting, pitching, or dragging). The first two methods, guys are doing it in extremely low gear with their 4 stroke outboard or with a kicker and the later is done under trolling motor power. Sometimes a person can anchor up behind a bar and jig, but things gotta be perfect. Do you plan on adding a kicker and/or trolling motor to fish? For just cruising around, what you describe would be alright. The river sections are pretty easy to read. Half the boats on the river are pontoons with 10 people on them and the other half are heavy V hull with props and few ever touch a sandbar (at least the sober ones). The biggest threat top to bottom of that system is the deadheads that appear and reappear in both the main stream and the reservoirs as the water levels fluctuate. Get electronics with route and waypoint storage and spend a little time mapping a path and deadheads and you're set.
A jet could maybe get you into a few tribs that a prop couldn't, but that would just get you to someone else's private land that you could just access driving in from the road. And most of the tributaries don't go more than a mile or so without being plugged by a dam, low bridge, or spillway. Lots of people with great info and a ton of experience are answering like you're about to run up to the headwaters of the Delta. For their reference, anything below Fort Peck on the Missouri is more like running a clear Yukon River.
