Rent to owns are rare and even more rarely are they worth pursuing for the renter/buyer. They sound good but in reality you are either a tenant with no more rights or responsibilities or an owner. You don't own until you obtain a mortgage and this generally has to happen within a specific time period or you lose your deposit and the over market rent you've paid.
For the vast majority of people resolving what issues keep you from buying now while just renting the least expensive place you can find is a better option. Most people looking for a rent to own have credit problems. Fix them, live on a tight budget, pay everyone on time, pay down your balances, save up as much money as you can and meet with a lender before you pay off any old collections or consider closing any old accounts.