Good Morning Folks!
Matt Burkett also sells mount for Doctor Optics style red dots. He has a new company called Predator Tactical:
I shoot 3 Gun as well and am a lefty.
Here are some of my competition toys!

I have a Trijicon Acog ta31-doc with a Doctor mounted on top.
I like using Trijicon Accupoint Scopes for hunting and competition.
No need for an extra red dot. The way it is designed you can shoot at 500 yards and shoot 5 yards from an attacking wild boar. By using the Bindon Aiming system with both eyes open, it works like a red dot.