Help me complete this 50 property owner finance deal

[Cade Collins]

I am 24 years old and currently house hack a duplex, Im a full time real estate agent and my goal is $30k per month by the time I'm 30.  I have been making 100 calls per day for a while, looking for deals and today I found a local business owner who told me he is interested in owner financing 50 properties all together in an up and coming zipcode in my area. I talked to him for almost an hour and we connected great, he said he is retiring and is wanting to owner finance his portfolio to a "young hungry investor" as he put it. I have a great connection with the number one property manager in my area who also has mentored me, MY plan is to come to an agreement and have him manage them all for me. this would be a great opportunity to take advantage of and I realize how rare an opportunity this is. I would like to negotiate 0% down, what are some tips and strategies to allow me to pull this off?