Elkshooter,
I buy Nicholson, Simmons, or Grobet for metal removal. But sometimes you can get them at wholesale outlets for a lot less. Keeping the file clean with a file card and/or chalk will make a file last longer.
A friend gave me a box of 10 that were made in Portugal. I thought that they would be poor quality, but they cut pretty good.
If I was to make a blade from a file, I would probably use Nicholson.
Lin