Varmint caliber?

[Baylian]

Which caliber would be the best centerfire varmint caliber for out west? I have never been varmint hunting with a centerfire rifle so I don't know what conditions are like. Some guys have mentioned shots out to 1000 yards. A friend says he's shot coyotes at 10 yards. So, we are talking about prairie dogs, rabbits, crows, coyotes, bobcats, etc. at various distances. That's a hugh diference in range. Should I get a varmint rig or a carry rig? Which scope and what power?

Thanks in advance, TJ