I suggest you try and get your hands on the Video Antler Giants. The hunting portion isn't great but they do go through measurements of different species of moose and it may help you with what to look for when judging a shooter in your mind.

If going with an outfitter ask them for pointers prior and upon arrival. Outfitters, guides are after trophies while the average joe like us is after a freezer. I always aim for the freezer if he has a mantle that is a bonus.