Each of these are valid approaches but the appropriateness of each depends on the true nature of the transaction and the motives of the buyer and big seller. 

Now if you use a private lender then it is whatever you can negotiate and get them to agree to.Banks and even hard money lenders want you to have "Skin in the Game" In other words they want you to have some of your own money at risk so if things go bad you are less likely to walk away.

@Calus Glispie the purpose of earnest money is for you to have skin in the game.

IDEALLY I would love to find an investor who basically has been doing this and wants skin in the game but does not want to deal with the head aches of the construction or management side.

I think his methodology is as much human nature as it is financial.

It seems like a natural succession for a large multifamily unit owner to also own their property management company.  

The exact nature of your legal situation will depend on many facts not known to me at this time.

You may want to look into something of that nature

Let a mentor-student relationship grow naturally.

I think the answer to the essence of what you're getting at here will be revealed by:1) What is the nature of this "little business" that you're starting?