Everything about this rifle is gonna be entirely your choice because we cant tell what will fit you good or more importantly what you want. The last rifle I bought I wanted a lightweight rifle, handled good, and I didnt want to spend a grip on a custom. I wanted to handle everything from mice to moose and then some if I need it to. I bought a browning x bolt in a 270 wsm. The reason I chose that round is ballistically it is slightly better than a 270 win. A 270 win is all anyone really needs in the lower 48 in my opinion. I already had a 270 win (due to sentimental value it has been semi-retired) and I wanted a new set of dies for the collection.
You are right a 243 will kill anything from mice to moose with good shot selection and placement. Just pick what feels good to you and what you enjoy shooting. Good luck on the hunt.