I'm looking to 11 Trophy XP Left-Handed in .308. What is the difference the regular and the International version?

I'll probably also buy a 110 Strom Left-Handed. What might be a good round for target shooting? I already have an AR .223, a Ruger Mini-30 7.62x39 and a couple of .22's. Id like something different. Would the .243 be good?