where to buy rooting hormone?

Walmart, Home Depot, Lowes, any store with a half way decent gardening section. Look for Rootone:

if you want to use some for home gardening honey will do the same job..

ebay or you better plant nursery, some commercial farmers supply stores, feed and seed stores.

http://homeharvest.com/cutstrtrootagents.htm

http://www.dipngrow.com/