Keep your money in your pocket.
Rent to own real estate is not the same as rent to own a tv or dryer. You do not need a take-out mortgage for a tv. A mortgage underwriter is not going to like the way you and the real owner write up the contract, do your research first.
I have never closed a take-out loan for anyone that did a lease option, and I have closed thousands of transactions. But I have spoken to a lot of people that lost a ton of money trying to use this method; anything you do to try and circumvent the rules that protect you puts your hard earned money at risk. The link below may help understand the deal. I hope my thoughts protect you and keep you from being hurt, good luck,
NMLS # 6395
Financing Kentucky One Home at a Time