I agree with most of the thoughts on size, type of boat. I fish primarily Lake Michigan with a Crestliner 18.5 Canadian. I too watch the forecast carefully and don’t go out when I know it will be too rough (3′ plus waves). I have also fished Lake Winnebago, which is a lot like the bigger lakes as you have described. Watching the weather is most important whatever kind or size of boat you are in.
I am an avid You-tube junkie also, I would recommend to all boat owners, to watch some videos on how to handle a boat in waves. In particular, bar crossings. I understand that you and I probably will never have to cross a bar, but the proper handling of your boat in waves is extremely important. Too slow and the wave coming up from behind can turn you upside down. Too fast and you will be pounding yourself and your equipment.
Fiber glass vs aluminum? I guess that you will have to make the decision for yourself. Well made boats come with hull thicknesses and bracing that will handle any type of water well. There are plenty of both types which are poorly designed and will fail. There are plenty of wood floors in fiber glass boats too. Take good care of wood floors. Take the time to research the thickness and bracing design that goes into the hull of either type. Fiber glass can, and will, crack and so will aluminum. Fiber glass is much easier to repair, and less costly.
The ride of aluminum is, generally more rough than that of fiber glass as the aluminum hulled boats are generally lighter than fiber glass. This causes the boat to be tossed about a bit more. But, it will rise more quickly in oncoming waves too. The fiber glass with it’s weight will generally be more stable and cut into waves more. BOTH will fail when handled roughly in waves. Another point that comes along with this argument is trailering. The lighter aluminum hull is much more pleasant to pull than it’s counterpart.
Another consideration that you may want to make is the layout of your boat. If you are planning to land the bulk of your walleyes from over the transom, then you will want to have a boat where the distance between the floor and the transom is shorter, so you can stand on the floor instead of climbing on the rear deck and/or ‘hugging’ the motor with your legs. far better to be standing on the floor especially in wave action. If I were to upgrade, I would definitely want a walk-through windshield, and a larger floor area between the windshield and the stern.
One last comment, to the fellow who will run a boat so hard as to ‘destroy it in a weekend’, I NEVER would want to be in a boat where you are the operator. Hull design/type was never meant to make amends for someone who beats his equipment and passengers like that. Must be nice to have lots of money to keep replacing stuff when it is beaten to death.
Hope this will help, good luck in your search.