Here are some questions to be considered:
While these are some of the major things to document, every transaction is a bit different.Include any special considerations that must be addressed. The Buyer is going to have his own considerations and you must be open to them.
Developing this agreement is very important because it avoids confusion. If you sell wholesale then, they will provide an agreement.
In my experience, more than 60% of the problems I have seen crop up when selling used equipment have to do with the logistics centered around removal. Most of those have to do with misunderstandings and that is why it is crucial to get it in writing every time!