I would go to any place listed under "Hydraulics & Pneumatics" in your yellow page phone directory and see if they can give you the name of the manufacturer of the machine they use to crimp the ends onto the hydraulic hoses they make up for customers.

It's very possible that they may even be able to order the garden hose ends suitable for crimping onto plastic or rubber hose from the same manufacturers that produce the ends for hydraulic hoses.