Something to consider is that traditional framing of home or building is a very well proven method that works very well. Pole barn style building is a very economical way to create a building that is very strong due to the fact that the poles are set in the ground and continuous up the length of the wall. When you set our pole on top of the ground, or on top of a footing of any kind, you lose all that inherent strength you get from the pole being in the ground. You now have a hinge that required additional engineering to overcome it's desire to fall over, or rack. I think perma columns are a solution to a non existent problem that somebody invented to sell to people who do not understand framing. When a building is built, the first thing you do is build up the pad. This has to be above the surrounding ground so water drains away from it. Posts in the ground do not rot from being in the ground, they rot from water sitting at the base of the post. Same thing happens with fences and any other post in the ground. It car rot completely through, but when you pull up the post that's still in the ground, it's in perfect condition. Once you have proper drainage, and then you put a roof over the posts and walls on the posts, they should remain dry and last a hundred years easily. If they get wet, then that's because somebody didn't do something right with draining the water away from the building.
Trying to combine the two building methods results in compromising their inherent strengths. Converting an existing pole barn is one thing, starting out wanting to build one and then putting the money into converting it into a house is going to cost more then traditional stick framing.
Eddie