One legged Johnny and the Christmas tree farmer both have good pee. I bought 5 gallons from Johnny last year and it’s hands down the best stuff I’ve ever smelled.
Trappers run in a pretty small circle in general, I won't think it would be hard to start a thread listing known collectors of coyote and bobcat pee. I collect for my own use. The guy I bought the cages from use to have a large scale commercial collection going on. I'm pretty sure he's out of the game now. Other than that I don't know of anyone except those listed above who collect. Grawes I believe claim to collect themselves.
I have bought and used urine from just about all the above, I think if you buy from trapper's that trap for a living you will get good stuff. I bought bobcat urine from reuwsaaluts from lure making and it's top notch. Just got wolf urine from O'Gorman's also from lure making and it's very wolf smelling stuff. Remember also to to gut and drain all bladder's from your own catch. Seems like snared critters have the most.