John,
I dont mean to sound discouraging, but IMO, thats a bad idea. One of the biggest problems with a permanent stand is the wind and the weather take a toll. That leads to a dangerous situation for you and possibly a buddy sooner or later. Its true pressure treated lumber will last and is durable. But you can almost buy you a metal ladder stand for the same price as the material needed for what you are talking about. It is almost impossible to anchor boards to the limbs of tree. When the wind whips hard like say in a thunderstorm, something has got to give. It will probably be the boards or the bolts. Some of these guys might know ways to get around all of that so "hang on"