Lease to owns are rare, and even more rare is finding one where the deal is fair to the renter/buyer. Little money actually accrues toward your purchase over the time and you are no more than a renter until you complete the transaction and make the purchase.
A much better option for most people is to find the least expensive rental you can stand to live in. Use the savings from rent and any other money you can find to address your credit issues and qualify for a mortgage sooner rather than later. It can happen fairly quickly if certain situations apply and you are seriously motivated.
Find a local lender who helps with credit repair. There are often mistakes made by those who do what "seems like" the right thing to do, but often isn't. Some safe steps are to pay down any balances you have to 1/3 or less than the credit limit. Pay everyone on time or early. Dispute any errors on your credit reports in writing with the appropriate proof of the error, do this with each agency that reports it.
DO NOT close any accounts or pay off any old collections, unless instructed by your loan officer as a condition of getting approved.
If you do this, you may find your credit can be in good shape in a few weeks or months. With a great lender, maybe even sooner. Once you qualify for a mortgage, you can pick from all the available homes in your price range and negotiate for terms that are best for you, not the landlord/seller.
I've helped and seen lots of people overcome tough times in their pasts, and I'm confident you can too.