The terms may be different but both are pretty much illegal. You will need a $250/hr attorney for about 300 hours to sort out all the laws. I would stay away. I suggest buy and resell on terms with a deed and a note and a deed of trust. Even this is considered selling sub2 which is OK to date but under investigation. Be sure your buyer knows all the details of the underlying mortgage. It has gotten hard to make a buck on Texas doing lease options or lease purchase.