Best Creative Financing contract in Ohio

[Levi Giafaglione]

I am in the process of looking at a 4/1 sfh for $64k.  The seller is willing to sell on terms but has had bad luck with the contracts he has previously used.  From my understanding there is a loophole in the Land Contract that made his previous tenants/buyers legally able to sell the house.  Is this not changeable?  Our realtor has suggested that we do a Lease Purchase contract.

I want us to both be safe.  Additionally seeing as how I will be rehabbing the property before my terms are due with him, will I be safe to do this without him selling/helocing it from under me?