Lender wants land contract to sell my lease option

I have a property that I have had lease optioned to a tenant for the past 2 years - the tenant has found a lender to write his new loan to buy it from me. However, the lender is requiring a land contract (aka contract for deed) to be signed by both parties before we can close.

What should I be concerned about regarding the change in structure? The lender is not requiring the document to be recorded prior to closing - should I put something in the additional agreements ensuring that the document cannot be recorded?

Take a look at the new contract they want me to sign: http://www.sapientcom.com/stuff/InstallmentLandContract.doc

Update: The lender will not allow an addendum to the contract stating that it will not be recorded until closing.

Will a separate document between myself and the tenant work for this?