6.5 PRC is a fine hunting cartridge, but it’s not a great training/plinking/fun to shoot cartridge for many people. Since this is your first rifle I wouldn’t recommend it, especially since you commented about not shooting much. If you already had a 6mm of some kind or 6.5 creed, shot it well, and wanted more, then it would be a good choice. On paper the larger cartridge always looks better, but you have to be able to shoot it. Many more people can keep a creed in the closet, pull it out and shoot well, than the PRC. Personally I’d pick the PRC as well, but I’ve given the normal disclaimers and warnings.
You’re probably set on getting the PRC, and there’s nothing wrong with that, just keep it in the back of your mind that if it’s not easy to shoot well right off the bat, with more practice and maybe a different shooting technique you’ll get the hang of it. A piece of carpet pad, thin flip flop, or a commercially available recoil shield makes prone shooting more comfortable if you have boney shoulders.
Have fun with the new rifle - anytime someone gets their first big game rifle I feel excited for them.