well ill throw in my two cents, on the guns listed go with the 243(no i dont own one), i would lean that way for a few reasons. Price, availabilty, accuracy, and recoil. you will need to shoot a lot to get familar and comfortable with the rifle, so there is price. if you buy ammo having alot of stores that carry the ammo around means you can shop around to get the best price. you need to get practice and dial the accuracy(mainly just finding what your gun likes to shoot). and recoil, yes everyone is different in how they process recoil, but i have never heard "man i cant feel the recoil on that gun, boy that suxs, now pass the 338 lapua"
If you want something bigger look at the 308, if you know someone in your family that reloads take a look at 7mm-08. best of luck with your choice and remember the xs/xl7 series uses win m70 scope mounts. ( i have a xs7 in 7mm-08, and love it)