ChiefG,
Hope I can give you some insight, as I am a sheep guide and see a lot of different stuff come through my camps/ conversations on packs often come up with other guides.
Money aside, there are three pack companies on the market currently that make incredibly high-end, purpose built, no BS packs for the backcountry (Sheep) hunter.
Mystery Ranch, Stone Glacier, and Kifaru. No offense to anyone out there running anything else, but if you want quality, comfort, and durability these are your three.
I personally use a MR Marshall 6500, have put around 300 days on it without any problems, rips, tears etc. If you tent to pack bulky, it can run a little small. Not the lightest pack on the market, but it also wont fall apart. If you have the option to try on several different packs (ideally with a decent load in them) this is your best bet.