This may sound harsh, but I suggest that you need to get your financial house in order before you consider moving forward with any intent on purchasing a home, even if it may be a rent to own. Keep in mind that in most rent to owns you are assuming many of the same responsibilities as that of an owner. These include the necessary property insurances, real estate taxes, and often times the property maintenance. The real difference of a rent to own and a traditional mortgage is that the current owner is your banker and that closing costs will be either reduced or deferred until the final title transfer.
The up side is that often the down payment may be less and your financial liability is lessened because the owner (landlord) is retaining that in their ownership. The downside is that if you default in any way all of your downpayment or prepayment monies are retainined by the owner/seller without recourse and you can be evicted with nothing to show.
I also suggest that you speak with a finacial counselor to assist you with your financial issues. Good luck.