First thing, talk to a Lender. Many will assist you in getting your credit where it needs to be for free. Watch out with rent to own. They can be tricky. Find you a good Realtor in your area. They can make this a much simpler process.
I have been seeing a lot of rent to own questions about properties.
With the decline in home prices and sales, I recommend you just rent while working to improve your credit. You can rent more house now in most areas cheaper then the payment if you bought the same home. Look in local papers and contact a local REALTOR to help you search for potential rent to own or rental properties. A good REALTOR should know how to guide you in improving your credit which could earn them a future sale. Good luck.