I assume you want a finished mirror, not a "kit".
Hubble Optics, Orion Optics UK, many retailers will sell mirrors usually GSO ones.
Where are you in this case a location is somewhat relevant.
Also budget - are you looking at GSO or Zambuto ?
Yes, you are correct. I am looking for finished mirrors so I can focus on building the scope.
I am near Annapolis, Maryland. (Bortle 7/8 area I believe)
GSO or Zambuto is above my level of knowledge. A quick web search says Zambuto has better contrast and is more expensive?
I have an Orion XT8 right now and am looking to build a 12 inch. I am a novice, but I finally found the Andromeda galaxy a few weeks ago, that was really exciting, so now I am really hooked and want to go a bit bigger, and then get into astrophotography. From all my research, a 12 inch Dob will be the largest I will need for a long, long time. Looking to build it myself and it seems hard to find vendors for finished mirrors. Any recommendations welcome!
I see kksmith gave me a good link, so will look at that for now and see if any other recommendations come back in this forum thread.