The Redhawk and SRH are a tiny bit stronger, but the SBH is more durable if that makes sense.
The RH and SRH will take a (slightly) bigger bang, but shot for a lifetime with full power loads, a SBH should hold up (slightly) better.
I have a Bisley Hunter in 44. I would say mine is a lot like the dozen or so other Hunters I have handled. The fit and finish is quite good with good cylinder lock up. But every one I have handled had a lot of creep and a pretty wide BC gap out of the box.
A couple of things bothered me about mine and I sent it out to David Clements to have it tuned up. I had a trigger/action job done, had the barrel set back to correct the B/C gap and the forcing cone cut to 11 degrees. I also had a different front sight made from a Bowen blank (a Bowen rear sight had been in place right after I got the gun) and a #5 locking pin. I had a number of other things done I don't recall right now.
I also found there was a slight constriction in the barrel at the threads (less than .001") but it took quite a few fire lapping rounds to eliminate it. The gun will now shoot better than 2.5 inch six shot groups at 50 yds, and handles like a hand tuned revolver should.
I tend to look at most Ruger's as base guns or kits to be completed though.