I am assuming that this is about a five hours trip from the time we leave Port Miami. This is a bit of guess, information from others that took this trip would be great.
Based on the estimation of five hours trip, I am considering to stop around half of the journey. The place that seems good is located at N24 56.477' /W080 36.444'. There is a TiKi Bar there, a couple of places to eat basic food and a small marina. If you guys have been there, I would love to hear about the experience. If there is a nicer place that I missed, please point out!
As for place to stay in Key West, we are comparing locations and cost now. Staying close to Duval street is a plus.

I will be refining my plans and posting here to share amongst us. Please contribute with suggestions or hints.