Mike,
Google "backpack load lifters".
Basically you want the weight of the heavy load to rest on your hips, not your shoulders. If you are 5-9 like Tutanka, the Crew Cab (or Longbow) IS going to haul a heavy load great. If you are 6-1 like me, the frame extensions (3") of the Metcalf and 6500 that are buuilt into the bag are going to help. Kifaru packs (most of them) have interchangeable stays up to 26" to create the proper shoulder trap anle to transfer the load OFF the shoulder and onto the hips.
You are getting answers here mostly from guys who are hunting way back and unguided. They need to carry camp all in and entire animals all out. These packs will all be overkill for a guided hunt where you are just carrying day hunting supplies.
If you get a MR NICE Frame, a Kifaru BT or DT based pack, or a Kuiu Carbon frame pack, you are going to be good for whatever you do. If you end up going on solo wilderness hunts, you can buy a 7000 cu in bag to go on the frame. Now you can go with a 2200-3000 cu in bag for your moose hun.t
If all you are ever going to do is guided hunts or local hunts, the best thing might be your MR Dragonslayer or Kifaru Spike Campr (or a standard Timberline 3). Kevin does not pack moose in Alaska with his DS, he has an external frame pack for the heavy duty hauling.
Sitka Gear makes great daypakcs like the Flash 32, the Eberlestock X2 would also be grand for your application. I am sure there are others, these are just what I have used. I've spent a lot of time and money looking for the "perfect" pack (and optics)
Both make a big difference in the field.