Ruger rifles don't "require trigger jobs"....that's a bunch of BS.

Look for Ruger or Remington, in that order. Both are great rifles, and ready to hunt with out of the box.

As for caliber, anything from 25 to 30 caliber will do you really well. Don't worry about it as much as bullet type. That said, if you can get a 308, 30-06, 7mm-08 or 270, go for it1

good luck