I have been going to the Keys for the past dozen years. I usually stay on Summerland, but have been throughout the upper Keys and have spent plenty of time in KW proper. A few questions before making any reccomendations
1. Are you staying in KW proper or are you looking at mid-upper Keys?
2. Will you have a rental car for the duration of your stay?
3. How long are you going to be there?
4. What types of activites do you and the wife like--partying, laid back, historical, fishing/wildlife?
Lots of options.
Some pics: