This is over a year old, SO WHAT DID YOU BUY???? lol.
Since he's shooting from blinds and treestands, I'd guess it's a smaller, private piece of land, so he's not walking a great distance. Fast snap shots also on not his priority. I'd pick whichever could be had with a med heavy barrel so that it was rock steady aiming. Put a lighter scope on it to cut a little weight you added with the barrel and make sure it has nice pointing balance. It's real easy to miss with a light wippy barrel. I wouldnt go overly long on barrel length either. Easy to run out of room in a blind, and branches could be a problem in a stand. You may not always have a rail or tree trunk or be able to use those shooting sticks, so get the one that points the best and holds the steadiest. Caliber is the least of your worries, they all work. There's alot to be said for the less punishing loads.