Should we consider a real estate attorney to draw up the contract or will a standard purchase agreement with a separate agreement that outlines those details suffice?

If this investor needs $4000 per month income, then 8 rentals generating $500 per month cash flow will suffice, or 10 properties each generating $400/month, or whatever multiple of cashflow and volume produces the amount of cash needed.My point is that your own goals and needs should dictate your investment strategy and determine the metrics you use to acquire your rental portfolio.   

It's probably much more complex than you need and a Promissory Note and potentially a mortgage (if they are lending for a particular property rather than to your entity) would suffice.

I understand that future capital improvements would be depreciable but if none of the value of the existing infrastructure can be applied towards the basis, it obviously reduces my after-tax returns.If the answer to question above is no, can I effectively create a defensible basis by getting a cost segregation done that breaks out the true value of the infrastructure or, would the appraisal suffice since the appraiser would presumably provide a breakout of the infrastructure value? 

Who knows, perhaps it takes longer than a week to do something with one's information but if that will suffice, why would he still be messaging me to complete the process?

Try using someone that can provide proof of income and you can give them a piece of the pie until you refinance or have your own income that will suffice.

But I would think if you close on a property from those lists, a couple hundred for the agent would suffice.

In scenarios where the cash flow IS suffice to cover the pref, it does decrease remaining capital that needs to be returned to investors.

@Randy Pierre and fha loan will suffice

A simple, hand-written note would suffice.