I'd use a red dot, I'm not a big fan of scoped pistols. I can hit a deer size target @ 100 yards with my stock G20 sights.
I've had a Redhawk with a scope in the past, the magnification was not my thing. It's all opinion, but it made it quite a bit harder for me to get on target and hold steady on the target.
If you do decide to get a scope, go low magnification and get the best one you can afford.
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