Discussion below applies to NEW MODELS (post-1973, also known as "two screw") only.
The Vaquero and Blackhawk are "basically the same gun", and most parts interchange freely (factory and aftermarket). The only real difference is sights.
The Blackhawk topstrap APPEARS to be "beefier" than the Vaq, which would affect strength - but in reality, the Blackhawk has that "step" at the rear of the topstrap for the rear sight which causes a "weak point" there. So the Vaq and BH strength issues turn out to be a wash.
But let's back up a sec: I said "weak spot" at the rear of the BH topstrap. That is a "theoretical issue" more than practical. On Ruger SAs where somebody has managed to grossly overload one with stupid reloading, Rugers are known for their tendency NOT to break the topstrap, even when the cylinder blows out. I've personally handled three blown-up Blackhawks kept at local ranges as "what not to do" (along with some other K-boom examples) and have seen pics on the web of others. Because the Ruger topstrap will bulge severely without breaking, safety in a worst-case scenario K-boom is improved, as the cylinder shrapnel goes sideways and no topstrap/sight fragments are added to the carnage and/or fly backwards towards the shooter. Blow up an S&W and typically the topstrap WILL break and even shed large pieces.
Upshot: custom gunsmiths such as Bowen, Linebaugh and Stroh will be happy to build up your choice of Blackhawk or Vaquero frame in silly-potent calibers like 454Casull, 475Linebaugh and the like (as a five-shot of course, to maximize cylinder strength).
SuperBlackHawk: still the same frame as the BH, as long as we're talking "New Model" (post 1973). The SBH will have a different hammer, slightly beefier barrel, generally a steel grip frame versus aluminim on a blued BH, and if the barrel is longer than 5.5" the SBH will have a larger grip. But the basic frame is BH.
Bisleys: same deal, only the grips/trigger/hammer differs in Bisley variants. Strength issues unaffected.