Hey Andrew T...good to have ya aboard!
It sure sounds like one grandiose project. If you pull the trigger, I look forward to following your progress.
...just a thought. Based on your presentation, I presume that the lake has not yet been constructed. Do you have solid evidence that there will be no construction impediments, whether they be legal, governmental, or structural? It would sure be unfortunate to find out that this is the real, underlying reason that the owner is bailing out.