I think you need to decide how much you would really use the rig on the rivers. Jet legs are often a compromise and their performance on a lake isn't what an outboard is, and on a river it isn't what a true jet boat is. It's kind of like a dual sport motorcycle. Not great at either, but a compromise that allows you to do a bit of both.
I've always thought that a guy needs a few boats because one won't cover all situations. Jet boat for the rivers, big aluminum fishing boat for the lakes, small fishing boats for remote locations/reduced hp lakes, and a ski boat for taking the kids tubing and wake surfing. In real life we all assess what we will use it for the most and make the rest a compromise.
If you decide to go with a bigger fishing boat, shoot me a message and I can help you out.
SS