I am looking into a new rifle for big game...like a .270 or 30-06...is that to much gun for fox and coyotes...would a 7mm work?

You can buy solid bullets for all of the calibers mentioned which should help hold down your pelt damage .They might be a bit much with a softpoint bullet .

a good dual purpose rifle would be the 243 up to deer size game.its not the most pelt friendly round there is on coyote and in most cases is to much for fox,unless your pulling 400 + yard shots.if pelts are a concern,none of the calibers mentioned are good predator rounds.

Exactly what do you plan to hunt with it? Don't rule out the .25-06. It is an excellent round for game up to the size of deer. I wouldn't recommend hunting anything larger with it but I'm sure it would work on elk or moose with proper bullet selection and precise shot placement. Handloaded with light bullets, good powder selection, and careful weighing it would make an excellent round for fox and coyote. As a bonus the recoil and muzzle blast are nothing.