mirror mount

I am looking for a reasonable mirror for a mirror mount project for my 20x80s. I want to mount the mirror and binos so that you can look down into the eyepieces. I have seen many prefabs units online, but I am interested in making one myself. I would like to know where I can find a good mirror, and what things I should look for in that mirror including type, coatings, etc.... Would I be happy with a front surface (or first surface?) mirror from the surplus shed? Or should I buy something of higher quality? I am not expecting prefection at this time, but would not like fog, distortion and false color. Thanks for any tips and experiences.
g

Gary,
Many of the rectangular truck replacement mirrors are first surface mirrors, check your autoparts store. You'll know it's first surface if you can hold a credit card to it and have the real card edge appear to touch the reflected edge. If you see a space between the edges it's not a first surface mirror.
DAve