Re: building a strat style guitar
It's possible to get a good finish with spray cans . . . it just takes more time and patience. You can buy cans of everything you need: a primer, the color, and a coating (gloss or matte).
Just sand after each paint coat, moving from a lower number paper to a higher number. More coats look better in both smoothness and perceived depth of the final finish. Of course there's a little more to it than that (For example, I don't remember the exact numbers on the sandpaper I used, but it was like 200 moving to 600.)