Welcome to HH. All the calibers you mentioned are great choices. I would suggest one of the calibers you already have in the rifle barrels (unless belted mag). This way you already have everything you need. It really won't matter because you have now been hooked and there will be many more calibers in the future...LOL

It takes 43 muscles to frown and 17 to smile, but only 3 for proper trigger squeeze.