Because of your mobility issues I feel it's important to have a great view and easy access to the water. For this reason I'm suggesting the Pearl Beach Resort on Bora Bora. This hotel is not as expensive as the FS or the St Regis but is, in my view, the best option. It has BY FAR the finest view of any hotel on Bora Bora and it doesn't overlook the rows of overwater bungalows of other hotels. The Pearl is on its own motu and has the absolute drop-dead gorgeous classic view. It also has a genuine Polynesian ambience. Go for an end-of-pontoon bungalow and you won't need to leave it and you just gently ease yourself off your deck and into the lagoon.