In the price range you seem to be looking there are a lot of good scopes that will last you a life time. You could just pick any and you would be happy.
But to get more precise advice you need to give more info.
You said hunting to 300 yards, all the scopes will be fine for that, but you said targets to 600yards.
What reticle do you want?
Do you want exposed turrets, or tall capped or short capped, or a Ballistic turret? There for need to track perfectly?
Is weight or size an issue?
Do you want illumination?
I would say the VX6 would be my choice, but if you want something for targets the 3-18 model mainly has hunting reticles that may not be best for targets, and it doesn't have turret that are quite right for serious target work.