Proto's are great. I wouldn't buy Snap-on there's just no need for that level to be used on a bicycle. Craftsman, Kobalt, Husky, etc are of the same level as Harbor Freight nowadays. Hobby stores sell some of the best hex tools on the market with brands like Integy, Ofna, and PBSwiss, but their pricey.

If you have an old set and they look worn on the ends, only about the first 1/8th of inch are worn, simply take a bench grinder and grind it down to just a hair below the worn out area.