Interested in buying a tumbler for my brass, are all tumbler's created equal? and what about the media, I see everything from corn cob grindings to abrasive stones with chemicals. How do I know what I need? Everything says "will clean and polish to a shiny luster" and can this media be used over and over? open to anyone's suggestions.

See the thread by Flitz from the other day. The vibratory tumblers with treated corncob are the fastest and most economical case cleaning devices:

http://shootersforum.com/showthread.htm?t=36717