While a 308 is a little overkill for yotes,it'll damn sure do the job.I prefer to use a 223 or 25/06 for yote killing.They'll both hit targets at 600 easily with practice,and the right bullet for the 223.
Some other suggested calibers would be the 243-260 Remington-6.5 Creedmoor-and 7mm-08.All of these are based off a 308 cartridge,and all will shoot 600 yards better than a 308.Factory ammo is also readily available for all of them,if you don't reload your own.
You might also think about getting an AR-15 in 223 or an AR-10 in any of the other calibers listed above.They come in real handy for multiple yotes or quick follow up shots if you happen to miss on your first shot.
Here's a few pics of my yote rifles-
Savage 12FLV 223 with a Boyd's LH thumbhole stock that I modified to fit the heavy barrel/1-9 twist,with a 6-24x50 Weaver Classic Extreme scope in Burris Signature Zee rings on a Ken Ferrell base.Rifle also has a SSS competition trigger installed in it-set at 2 lbs.
Rock River Arms 20" Varminter 223 it also has a 6-24x50 Weaver Classic Extreme scope on it.The photo is old and shows a different scope.
Savage 110FLCP 25/06 in a Choate tactical stock with a Sightron SIII 6-24x50 LRMD scope in Burris Signature Zee rings and a Ken Ferrell base.Along with it's 308 twin a 10FCP with a Sightron SIII 6-24x50 MOA-2 scope,same rings and base.
I just put a 7mm-08 together,and have a 6.5 Creedmoor barrel to build another rifle,or just swap out the barrels with one of my current rifles.
That's one of the reasons that I like Savage rifles,they're like adult lego kits,if you want something different,just take it apart and change it into something else in a matter of minutes.
Remington,Howa,Tikka,and CZ also make some great varmint style rifles.
When it comes to optics,Buy the best that you can afford.It's always best to get what you want the first time,even if it takes a little longer to save for it.