The most efficient way to find cash buyers that I have done is filtering the county database. It can sometimes be very technical and sometimes not. You can go to the county and ask for the entire database of properties. I've found this is possible in many different counties. I've done this countless of times. My buyers list is the size of King Kongs left index finger. When I'm done with the 4 counties I am preparing to market to, my buyers list will soon be the size of King Kong left hand. I pay minimal dollars to acquire all my buyers and I have a sweet system that I use to manage and contact them.
I would highly recommend NOT buying a buyers list and blasting emails and text messages to them without introducing yourself like everyone else does. But if you are really good at reading what the cookie cutter buyer wants you don't have to contact them until you found exact what they already have brought. I recommend building a relationship with each one of them if you can.
If you acquire a buyers list the way I did you will find buyers in different counties, states and in my case some in different countries. Try to think outside the box and look for places where a turnkey buyer might live, ohh lets say for example the (SEC) Security Exchange Commission or a lawyers or physicians directory.
A very influential person once told me that "you get out what you put in". Let me know if you need help with anything.