I will see if I can drive a blazer before I buy one, that's always good advice.
Most of the times I am at the dunes the windows are all down the entire day and never go up. In fact, I was wondering if they made vinyl windows for the side doors that I can velcro or zip up, like they do the back, so I can eliminate the glass and mechanisms in the doors. I do like the manual vents in the cowl/footwell, and the the vent windows. In fact the cowl vents are almost always open to allow fresh air to flow through.
I am leaning toward converting a newer one now because of the leg room.
But I am not getting this to be a daily, or something nice as far as creature comforts. I don't even know if I will put wipers on it. A heater probably. It will likely be no carpet at all, with a cage, and vinyl suspension seats. Leg room does sound appealing, and also looks like it would be a lot easier to get in and out of the back seat. I will probably keep 4 speakers in it. I will probably use a truck tailgate because its lighter and I like tailgates.
Also, the suspension and steering will be custom, nothing factory, no leaf springs.
To be honest, I'd want to build a 4WD dune buggy within a blazer tub. But I want the tub to be nice and not rusty or dented.