I agree with Jean. The price range you have indicated is very low for the Dallas area. Rental rates and home sales are all up this Summer due to high demand!
With regard to Lease to Own option, always employ a Real Estate attorney before signing any contracts. In my Real Estate career, I have come across many people who got into these deals and had problems. Be safe and consult an attorney first!!
The Lease to own option is not one that a Real Estate Agent can prepare for you. You would have to hire a Real Estate Attorney to prepare those documents. It is better to just Lease something and when the time is right for you to buy then do so.
Good Luck on your search.
William Davis Realty