I'm a Goodyear MTR guy. Any tire with a mud tread is going to be noisy, compared to an all terrain. I don't notice the tire noise much on my 40 because the soft top noise drowns it out. I use the Bridgestone Revos on the wifes 100 series. They just don't look as cool as a good MT. I'll be talking to a guy today that just put MTZs on his truck. I'll see what he says an let you know.
I spent 3 hours Friday evening on it, and about 9 hours on Saturday. I'm kind of a slowpoke, I guess, because some folks forecasted 5 hours total.
It is a fun project. I recommend doing it yourself as opposed to paying a shop to do it. It'd be great if you could find an experienced Mudder nearby to help you get going and offer pointers.
Just heard from Jerry with the 285/75r16 MTZs. He said they have a hum to them, but not too loud. ATZs should be quieter, but have no first hand experience. Get the tires that you like and don't worry about a little road noise. It helps scatter the squirrels anyway. (Not like splatter-scatter, but scare them out of the way type scatter)