Don't know if you have made any contact with a local agent in the Windermere / Winter Garden area or received any answers to your questions so thought I might could help.
My wife and I are both Realtors and this is one of the areas we specialize.
Within the community of Isles of Lake Hancock you have a mix of existing home resales and vacant lots for to-be-builds. Currently there are 2 resales and 1 lot for sale in the community.
Around the same lake, Lake Hancock, you have 2 other communities that offer waterfront with new homes and existing and another we just received the heads up about that is going to have a marina.
You can contact me through Trulia by viewing my profile. Hold your mouse pointer over my picture and in the pop up look for a link view my profile and click.
Broker Dave & Patty
GRI, ePRO, REPM, CDPE, GREEN