I guess I was only partially responsive to your initial request. Sorry.
You had asked for cost estimates. My experience is long enough ago that it’s no longer relevant on actual costs. But a good rule of thumb, I found, is to make the best estimate you can, tallying up the prices of each individual item, and then double it–there’ll always be stuff you didn’t know about until you started to tear things apart, and they tend to add up. Bolts, wire connectors, spray paint, shop materials, etc, tend to add up as well.
Also, you’ll need space. I found that I needed the equivalent of another garage stall to store the parts I’d removed, plus maybe a bit more space to actually work on those parts. The space should be enclosed, warm and dry, and, probably most important, it should be very very close at hand, so that you can go out after dinner and putter around with a part from the truck. Having to drive clear across town to a storage facility is a major demotivator.
Krylon gloss black enamel is your friend. Dries fast, really fast. I also used a lot of rust neutralizer–don’t remember the brand right offhand–and Rustoleum damp red primer. Rustoleum damp red primer stinks to beat the band and takes a long time to dry, but it’s got anti-rust ingredients the others don’t.
Don’t do anything half-assed. Buy the right part and fix anything you see wrong.
Rebuilt alternators are, generally speaking, crap. The letters pages of Street Rodder used to be full of people saying that their charging system problems disappeared when they finally gave up on rebuilds, and spent some money to get a new alternator from GM.
Look into a new wiring harness, especially if other owners have been in there, splicing and revising.
Body rust repairs: Surface rust you can maybe get by with grinding off as much as you can, treating it with neutralizer, applying Bondo, and repainting. But if the old paint is bubbled, the panel is rusted clear through, and the only proper way to fix it is to either replace the whole panel (if it’s easily unboltable, like a fender or hood or somesuch) or, if it’s not easily unboltable, to weld in a patch piece, which is not for beginners; I had major problems with warpage. (I was using an acetylene torch, though; perhaps a wire-feed, which puts less heat into the metal, would have worked better–but I screwed around with a friend’s wire-feed for a bit, and there seemed to be quite a learning curve.) If you decide to use an acetylene torch, what worked for me was to use a filler rod about the diameter of the sheet metal thickness; eventually I ended up using steel wire as filler rod.
Dented stainless steel trim bits can be repaired by gently pounding out the dings from behind, filing the surface smooth, and then goin at it with a buffing wheel. There isn’t much you can do about dented aluminum trim bits–they have a clear anodize finish, and if you file on them, there’s no good way for the amateur mechanic to restore the finish. Take a dented steel bumper in to the chrome plating shop and get them to straighten and replate it.
Replace the windshield rubber, and while you’re at it, look for rust-throughs in the body channel the windshield sits in; that’s the cause of the mysterious drip on your feet that you can’t seem to fix by caulking the windshield with silicone sealant.
Don’t use silicone sealant for anything. The silicone gets all over and then paint won’t stick, and it isn’t a very good sealant anyway. Use one-part windshield adhesive/sealer–buy it from a local auto glass shop.