Welcome, taihawk! So you are dealing with a few things here. Let me split up your question a bit and maybe you could comment. That might help us help you.
1) Learning to shoot open sights with your non-dominant eye...have you begun to practice this new skill with a 22 pistol? This could start to develop your other eye.
2) On your hunting rifle, are you going to switch your entire setup to your non-dominant side, or merely twist your head to sight with your non-dominant eye? What do you want to change to deal with this setback?
3) Are you looking for a range-finding optic as part of your scope or a separate unit?
.45acp, .40 S&W, 9mm, .38 Spl, .380 acp, 22lr
12 gauge, .223/5.56x45mm, 30-30 Winchester
2 Chron. 7:14 Christians must seek His face