As revered Clint Eastwood is in pop culture, I doubt Sideshow's ability to do it properly and respectfully with quality.
If and when this line sees fruition, I wouldn't be surprised when third-party offerings and hopefully superior ones at a more friendly and reasonable price level come into play.
If I had to pick one stand alone character I'd buy provided it was done properly with quality, it's Josey Wales.
To me, Josey Wales > William Munny.
In the same token, "The Stranger" (High Plains Drifter) > William Munny.