Some of the FX shops I've worked for in the past:

Make-up & Monsters

c/o 21115 Devonshire Street #109
Chatsworth, CA 91311
Phone: 818-886-6587
Fax: 818-709-6587

KNB EFX Group
Phone: 818-341-1484
Fax: 818-341-1526

Optic Nerve
Phone: 818-771-1007

Make-up Effects Lab
M.E.L.