In response to your question regarding the ball mill, I use a 1" diameter carbide ball mill with a 1/4" shank available through one of these sources:

Santa Rosa Tool
Santa Rosa, CA.
(707) 545-6480.

Sev-Cal Tool Inc.
3231 South Halladay
Santa Ana, CA 92705
(714) 549-2211

Fullerton Tool Co.
121 Perry St.
Saginaw, Michigan 48602