Rent-to-own is a horrible, horrible idea for the buyer. They homes are usually in horrible condition because the seller can't sell any other way. Renters pay a surcharge (above market rent) and you lose your money and deposit if you decide not to buy the house, or if you can't qualify for a loan. Seller hope that you will violate the terms of the agreement so that they can resell the house to the next sucker.
I strongly suggest that you continue to rent until you can qualify for a traditional mortgage; then go shopping for a home. Put the money that you would have spent on the surcharge into a savings account. Fix your credit. And before long you'll have a home of your own.
When you want to buy a home the best place to start is to hire an EXCLUSIVE Buyer Agent, not just a Buyer's Agent. EBAs only work with homebuyers and there is never a conflict of interest that will jeopardize your negotiating position. I can refer you to an EBA in your area, if you like.
I've written a best selling book called Buying a Home: Don't Let Them Make a Monkey Out of You. It'll teach you how to buy a home and get a mortgage without getting ripped off. Follow the link below.
Best of luck!