All these choices are great. However I would suggest in first determining when you will be doing most of your hunting. Are you going to hunt in low light areas or during dusk. If you dont need to have heavy light gathering then thats what you look for. Take your time and make sure that the scope on your 300 has a comfortable eye relief as those 300 WSM can thump. But Im sure you will make the right choice.
I personally am a huge Zeiss fan and they make great optics.