Which financial structure is best?

[Erika Murphy]

I have an opportunity to buy an empty, zero mortgage house from an elderly seller. Not a family member but close enough. 

Seller doesn’t want to pay the tax on the sale or manage the house anymore.  

Would a lease option achieve this if the seller passed away before the contract came due?
Is there such thing as a lease option that ends with a TOD? Something like à viager arrangement.

Open to suggestions.

Thanks