I'm not trying to discourage you in anyway, but even if you get the ones from stew-mac there is still a lot of practice needed to pull of a nice nut slot. Personally, I have a set of stew-mac nut files...however I do repair work as my job, so they're worth every penny. I've already made my money back and them some. Another way to go is a triangle file. They work very well and I still use them for basses. The slot ends up trianglular but after you're finished slotting you will sand the top of the nut off and you can't even tell. A triangle file probably costs, at the most, a few bucks for a good one(you don't need a large t-file, small ones actually work best). Get a few different sizes and see which you like. Really it all comes down to which feels most comforatable for you. Honestly, if you aren't planing on making nuts on a regular basis then you might not want to spend the money on the stew mac stuff. Have fun with your first project!