How to negotiate private deal with neighbors?

[Patrick G Whynot]

Hi folks! I'm looking to get creative in an attempt to consolidate properties in neighborhood of my primary residence. 

I have a number of elderly neighbors who have been here for 20+ years and I expect they will live out their remaining years in current house. Does anyone have experience doing private deals with elderly folks wherein they remain in the home? 

What is the best structure? Different approaches?