If you know your rivers well and can stay in the channel, get the tunnel hull. It will be much more efficient than the jet and work well on open water. If you need to go skinnier than 8-10 inches you'll want a jet. If you like exploring and running shallower water than you should (like me) get both. Yep, a jet foot and a small tunnel to further protect it. You lose about 20% of your thrust to the jet which means you need a bigger motor than you would with a prop= more weight and gas. But man is it a lot of fun.
This is a great resource for jet info: