At K9 PRO we have some seriously good Leather Harnesses
I truly feel that after working dogs in harnesses for many years, ours have the best functionality due to the 5 points of adjustment, breast plate with recess for air flow, saddle and quick release clips.
Many years ago people would work dogs on collars, some even check chains. Over time we learned that these were taking drive out of dogs and started using wide, flat leather collars which will distribute the pressure over a larger surface. That was a START.
Working a dog in drive should be done in a harness, I still from time to time see a dog being worked in drive, perhaps by a decoy and the dog being restrained by a check collar. The dog is lunging into the collar and its neck bearing the brunt.
If you own a Rottweiler, German Shepherd, Doberman etc. you really will love these, they make your dog look (even more) AWESOME.