I fully understand the part about one's hand being smacked, with the factory wood grip panels in place. Yes, Pachmayr will help, but unless one has very large hands, it may not be possible to reach the trigger in the DA position while keeping the grip properly centered in the the web of the hand. My hands are certainly not big enough to handle a Redhawk, or to be more precise, my index finger cannot reach the trigger well enough for SA shooting. If I have to cock the hammer, anyway, to reach the trigger, I will go with the much handier Blackhack, and in fact I do have a wonderful stainless 5.5" Blackhawk Bisley. I did own a couple of Redhawks.
The Super Redhawk is an option, and does fit me, with a GP100 grip installed. My SRH is an Alaskan snubby.