Grass. That's the toughest call. Something like a Gator Tail or Pro Drive would certainly fit the bill, however they suck riding long distances through open water and I don't think they are in their element on a remote steer setup. You need tiller on a mud motor.

I am not familiar with the Mobile Delta's backwaters so I don't know if the grass is matted all the way to the surface or a lot is underwater and how thick.

If it is real thick and matted on the surface only thing that will go through that is a mud motor or an airboat. Even with a tunnel you'll channel that grass up into prop if it is all on the surface. If it is 3-6 inches underwater.... now you can get into jack plate and outboard discussion. Combo Jack Plate and Breakaway plate. Your going to slow way down and put put through the shallows but you'll do pretty well even with a lot of trash in the water as long as you don't go fast hit a stump and mess up the foot on the motor. If you had a tunnel hull You can also build a knife into the tunnel to cut through lilies and keep trash from getting channeled into the prop.

What it really boils down to is how much of the ride is actually going to be in the grass. 3 miles across the bay, up a short canal and then a couple hundred yards across a grass flat... if we left the ramp at the same time I can get there and push pole the majority that kinda distance before you could get there with a mud motor.

Longtails suck in open water. Slow. Heavy. Hard to steer and will generally wear you out. They pop out of the water in waves and you just have to generally wrestle with them. So I would rule that out unless you are putting in the boat close to where you are going. They do work better on a hard bottom than a surface drive though.