Private purchase agreement opinions

I have an opportunity to own a truck and trailer on the prairies hauling logs .

The truck is a 2013 Pete , 180,000kms , paccar mx13 (485hp) . The trailer is a 2006 Doepker super B logger .

The owner bought the the setup with his son in law in 2013. The son in law decided he didn’t want to truck anymore just a year into the venture . The father does not drive and is retired . He wants out of the deal .

I told him , the only way I can purchase the truck is basically a lease to own type agreement with him . We discussed some very basic terms and ideas regarding the agreement . He then asked me to draw up a detailed agreement to my liking and he will get his lawyer to look it over and approve it .

Im a go getter , very experienced in the field , and have an entrepreneurial spirit !!! I’m excited for the opportunity. I have been in business in the past and realize that it’s not all roses and rainbows .

I have a general idea of the details I’m looking for but want input from Canadian O/O.

What I’m looking for is ideas on some of the terms that I should include that are fair to both parties.