Beverly, it must be frustrating to find homes you're interested in but do not want to rent or offer a rent-to-own option. Most times this is not put in the MLS and if it is, the remarks may sometimes only be seen by real estate agents who subscribe to the MLS. MOST rent-to-own programs prey on those with less than perfect credit and is a decent option if you are okay with the results - above market rent (usually) combined with a market value sale down the road.
From the seller's point of view, just as you may not be able to afford buying a home, did you consider that they may not be able rent it out for financial reasons? If their mortgage (principal, interest, taxes, insurance) is more than the market rent, it probably would not make sense for them to take a negative hit each month to rent it out.
If you are truly set on home ownership now, expect to pay more than someone who has the finances to buy now. I would recommend that you consult with a local real estate agent to obtain real advice from someone that knows your market. My view and opinion were general views and to gain specific advice, one would have to be licensed in your state and have knowledge of your personal financials.