FYI ... Realtors in TX are not permitted to participate in rent-to-own transactions ... you'd need an attorney to prepare two sets of documents, one for the lease, the other for the sale.
There are other issues as well. Contrary to common beliefs, there's a large deposit required, little or no rental charges are applied to the down payment, the interest on the sale portion is much higher (at least twice the going bank rate), and you'd still have to obtain financing in a couple of years to pay off the owner (the "balloon"). They're great deals ... but not for the tenant/buyer.
Please give this some serious thought ... I wish you well.