This is the contract that I used which acted as a safeguard for a large Physical Bitcoin transaction (which could be modified to meet your needs).


I
highly recommend
themeeting inside of an airport
for several reasons if doing a large transaction and meeting in person. I can come back to this and list my reasoning later.
Another recommendation is if you create a contract for a transaction follow it to a T. Do not do anything outside of that contract and make consequences for those that do.
Require an ID from all parties which includes a picture of their face with their ID held up next to them. Your agreement can even state something along The lines of that information must maintain to be private, unless agreement is broken.
They’re 1 million ways to go about this. - plenty of good ways
& plenty of bad ways. The whole idea is
for you just to minimize risk for all parties
involved. Also to incentivize both parties do the right thing.