It would be the same process as any other FSBO sale you just need to close the transaction prior to the auction.

Zillow has a great data product you can run and see rent trends, DOM, etc for a given zip code over a defined period of time.  

Be honest when the last time you bought something on Amazon and didn't read any reviews or even gandered at how many stars the product has.

Maybe you're an attorney, but I think that report can be shared with any interested parties in that transaction.

Just wondering what the best way to find out where most cash transactions in a given area occur for property purchases?

From a position of attracting buyers for the homes surrounding the airport, it certainly does that and helps boost the home prices.

Due to an all cash transaction, the initial risk is the deposit.

They could do a "subject to" or a "lease option" transaction depending on their personal needs and title position need and how much they trust each other. 

I also reached out to some of the investors and they seem interested in it but how do we go about with the transaction?

Run your cash flow numbers over the next few years and see how long it takes you to hit 20% in equity (don't forget transaction costs), and there is your target date for the refinance.A 4-plex is considered a residential loan vs. a commercial loan for your 40-unit, which are structured very different and won't have as many low/no money down options.Sounds like a great opportunity!