Steve Guitron, Bill Black, Ortiz, Ortega..just to name a few. Also know a guy in Oregon that does beautiful work.
A good hackamore bosal will cost you a couple hundred bucks. Which you will get what you pay for! So if you don't go with an expensive one, at least get one with a rawhide core the cheap ones are built with a cable. And you can tell the difference between bad braiding/crappy rawhide and good. It is pretty obvious. The plaits should be tight, smooth and even. You shouldn't see the core peeking through.
I DON'T LEAD 'EM AND FEED 'EM, I RIDE 'EM AND SLIDE 'EM.