All 4 of mine came from a rescue. They are weird people generally, so there were challenges. Biggest one was to get them to stop offering me 15 year old females. It took about 6 months and then they got a batch from somewhere that had some young males.I don't know about pack llamas from a breeder, but we have been able to find 5 pretty decent animals in the last 2 years through a lot of searching. They are mutts and top out 300 to 330lbs, but they work. After we got one or two we started holding out for llamas that were heavy muscled and better confirmation. I probably looked at 30 or so till I would see a good one. If I didn't call right away it would be gone. That happened several times.
I also talked to adoption agencies. If you find a good person and are willing to wait, you might find some decent ones that way.
Keep looking they are out there. You also have to be willing to drive a distance to get them.