Tom has a good bit of advice. Having been to Ginko, and seen the quality of Mugos there, it is blatently obvious that these trees are excellent bonsai material.
Another good place to check out nice Mugos is on Walter Pall's site:
http://walter-pall.de/galerie.htm
You must also remember...these are originally wild mountain yamadori, not the junk sold in nurseries!
Flex (another co-founder of 4MAAT)