Thanks for reaching out!
The Granite Gear Blaze 60 pack is a solid pack and will likely serve you well on your trip, particularly in regards to the hip-belt padding. While it is just a hair under your volume requirement, have you considered the REI Co-op Flash 55 pack? It hits your other needs and I have spoken to folks who have used it on the PCT or other long distance hikes and they rave about how comfortable it is.
We're going to move this post over to the backpacking board to see if anyone in the community may have insight that can help you decide.
Hopefully this helps, thanks!