As others have already noted, the Bearcat is going to be just as tiny in your hands as the 63, in fact it will probably feel tinier, and the trigger pull won't be as good. I've always wanted to like the Bearcat and had one briefly a few decades ago but just couldn't get around the small grip and short reach to the trigger. Plus there aren't a ton of aftermarket grips available that would radically change the shape.
Have you thought of a 4" Ruger SP101? The stock grip still feels kind of short to my hand but aftermarket Hogues or Pachmayrs are readily available to lengthen it without adding a lot of girth. At 30 ounces the weight is about halfway between the Smith J and K frame revolvers. DA trigger isn't anything to write home about but then neither is the Bearcat's.
SA trigger on the ones I've tried seems okay and IME Ruger triggers generally wear in to be better than they are out of the box.
