Be prepared to pay extra $$ for a 1/10 wave mirror (peak to valley). Most commercial mirror making companies don`t promise much better than 1/4 wave, peak-valley. But don`t let the price fool you either. High price doesn`t always mean high quality and vice-versa. I bet there are some used high quality 10 inchers for sale out there at a very good price. Also, in the back of Sky & Telescope magazine there are usually ads for mirror making companies.

Before forking over the bucks, make sure you understand what you are buying in terms of quality. "1/10 wave" may really mean that the mirror is only 1/5 wave, peak-valley. If this is a bit confusing, check out this this site for the many ways mirror quality can be defined:

http://zebu.uoregon.edu/~mbartels/mirror/ratemirrors.html

Good Luck,
Bill
http://my.treeway.com/observatory1