If the Crichtons are involved, that chemistry is going to be there in *spades*, 'cause Ben and Claudia worked together for both Farscape and SG-1. They'll get into character as if slipping on comfy gloves. I suspect the others they bring back, if they do, will be equally up to the task of being who they were in the show.
Only wildcard here, I think, is a poorly chosen actor to play the part of D'Argo Sun-Crichton.