So sorry to hear about your husband, It sounds as if you are doing all the right things, and Dr. Bochner (MSK?) is a great second opinion. I am not an "expert" on chemo, so can't help much with questions there.
At your husband's age a neobladder would be a great option. He will want to have a surgeon who does MANY MANY of them, as "practice makes perfect" but it seems as if he is probably in such a place.
Best wishes to you both
Sara Anne