#1
Okay so this guy on craigslist is selling this strat body for $50

Where could I go about buying an affordable neck?
I would use the one off my old strat but I bought some machine heads at GC and was sworn that they would fit my strat and sure enough, I get home and they were to big for the original holes, so I had to make them wider, so after that I fit them in. The screws didn't match up. So I had to make new holes for the screws, as soon as I drill in the first screw I get a hairline crack on my headstock, drilling any deeper would've cracked the headstock to the nut, and then the tuners were hanging off the neck a bit and they were too far apart for the screw to link them together.
They were these

So now I just have extra tuners with no headstock to call home.
#2
eBay if you want a Fender neck or some licensed ones from AllParts, Mighty Mite, Musikraft, etc.

Make sure to match the diameter of your Kluson/vintage-type tuners with the neck you're buying. There are many Fender tuner variations as you've discovered.