I would visit zillow on homes for rent and pitch the landlords this idea and sell them on the upside of how much more they can produce and how you can make it passive. They are your perfect client because they already have the inventory and are just focused on profits. I will add you have to be extremely resourceful in the process of furnishing to really diminish the investment they have to put up front. Something else that helps is go for properties that are similar to your existing listings so you can show real time numbers and will give them an added level of confidence. This is the route I've took to manage properties. I hope this helps.