It would be rewarding and great to do a rescue, but from all you explain and the timing be what you want.... a puppy or a young (under 2 re-home situation) might be best for you and your life style. Regardless of age, a new puppy will be easiest to introduce to Bentley as most dogs just accept a baby, be best to go with a female as opposite genders tend to get along better (not all but higher percentage).
When Banks' past, we wanted to rescue, but when we sat and talked about it and knowing Chelios' (our Frenchie) personality along with our schedules and life style, the timing was just not right for a rescue. We did a foster for 2 weeks and Cheli wanted to eat her, Banks seemed less interested, but would stare Mia down from a distance (never in the same room or on same floor together). We also took Cheli to a few dog walk events and he did not do well at all, so with all that in mind, we knew in the best interest of the pups getting along ... it had to be a baby.
I someday want to have 3 or 4 rescues, but it will have to wait till I am home more -- right now, just does not fit the schedule
best of luck with your decision!
As for breeders.... look on the Bulldog Club of America site or AKC and then do TONS of research