I would strongly recommend using a realtor with a land contract, your realtor should not cost you any money out of pocket and is obligated to represent your interest in the matter. Land Contracts can be more complicated and you need to make sure you and your wife are protected.
Best of Luck
This is going to be more complicated, and I suggest (don't always) using a Realtor in this scenario. Having a buyers agent in your corner should not cost you any money, and they will be able to provide you with the best guidance and representation in this situation.