Don't know what your definition of "good quality" is, but there are a few local cake & candy supply stores that you could check out. My mother-in-law runs a similar business up in LA, so these are the two businesses that she's had friendly dealings with in the past:
Do It With Icing in Kearny Mesa on Clairemont Mesa Blvd:
Standlee's in Chula Vista on 3rd St:
I'm pretty sure they both carry Merckens melting chocolate, which is kind of the standard in the cake/candy craft world.