If you're not getting surgery until december, honestly I'm not sure I'd be planning on anything resembling a full sled season.
I'll be wearing a CTI brace all winter because I had ACL surgery as well, but that was in April. I've been pedaling bikes up mountains all summer. You've still got the whole full atrophy thing post surgery to go through. I'd be looking at spring time for anything other than sitting on your arse trail riding stuff. Don't screw this up. If you hyperextend your knee before whatever graft you get has been incorporated into your own tissue, you're going to have a useless knee until you decide to get surgery AGAIN to fix it. I've been through 2 ACLs and 4 knee surgeries total. Let it heal. You're young enough that it will happen right if you let it. Be sure to do that and don't get caught up in whatever happens snow-wise in january and february.
But your ortho will give you all your options in terms of brands. One thing I don't like about the recovery with knees is that no one wants to do a custom brace until 6 months after surgery. My thoughts on that were, how the hell are you supposed to build your leg back up without excercises that potentially screw up your graft? For that reason, I got an off the shelf CTI that adjusts as your leg returns to its normal size. That way it's protected as you start using it again. At the very least I'd say go that way. And if you want, you can get a custom fitted one once you've returned to baseline.