In many of the MLS systems there is a field for Lease? or Leased. You can make an offer on any home subject to your terms. The worse thing that can happen is the owner says No. If going thru a Realtor, sit down and go thru the MLS, pick out all the homes you are interested in, then your realtor will or should call ahead to the listing realtors and ask if the owner is open to a lease option. This will cut thru the pack.