I live in Missouri and am looking at getting a mud motor/boat setup. I really like the Prodrive rig and was wondering what would be a good fit for big water such as the Mississippi and Missouri rivers but also put the boat in a lake or marsh. I do not know whether an 18 inch sides or 21 in sides would be better? I mostly duck hunt and from time to time I may run up a shallow river with gravel bottoms where the water depth may be 2 feet deep. PLease , any advice would be appreciated. There will 3-4 hunters in the boat.

I run a tall side and tall transom PD boat.
I hunt in venice, LA, and have to cross the river every trip.
I got the big boat b/c of tankers and crew boats, that I have to deal with here in the Mississippi river. I haven't had a problem or felt worried with the boat. (even when at the bottom of the wave, I couldn't see over the waves, and I was standing while driving)

I think tall transom is just as important too...

What they said

Thanx for the feedback. It looks like I need a tall transom, tall sided 1860.

I run open bays and ICW a lot having an 1860 makes it very stable and I agree it can handle some good waves. I have flotation in my GTB cause I run these open areas, just something to think about as your deciding on options.