I'll throw in my 2 cents. Firstly there is nothing wrong with wanting to keep a car to work on as long as your aware of the amount of work and $$ it's going to cost you do get it done, which will be a lot cheaper than having someone do the job for you but nevertheless it will cost.
For the heavy rust I would start by getting a body hammer or a ball peen one and "lightly" tap all that rust. You don't want to dent the metal but see if it gives. If it gives then the metal is rusted through and you'll need to either cut and replace sheet metal or just replace the whole panel.
I would do this first cause that will dictate how the rest of the project will flow. There's rust and then there's rotten out panels. The first can be dealt with cheaper and easier than the second.
Door's panels (or just bottoms), fenders, hoods, and quarters can be replaced the roof and windshield pillars on the other hand are another matter. They can be replaced and I've seen it done, but it takes a lot of experience and the right tools. Patches can be fabricated and welded in, I've done it and other board members have as well.
I would pull the windshield and any trim around the doors and start with the roof. Get a quote to have it blasted as that's the best way to deal with the rust your looking at there.
If you can get past that without breaking the bank or your will, then the rest won't be that bad. Like I said replace the panels/hoods if you have to with one's from the bone yard that are in better condition.
One thing I wouldn't do is strip the whole car at once unless you have some place to keep it indoors.
Thoughts and comments expressed by me are mine based on my own experience and research and shared here freely. I am not a professional nor make any claim to be as such