When my business partner and I were still flipping we bought a couple through Auction.com and we always used a private money lender to fund those and our other flips. 

Feel free to private message me with any additional questions.

I financed the acquisition of the land with personal and private money.

Sometimes they'll have gurus come thru that charge more for a full day class or more extensive training.I've posted before some lists of area meetups...each has a little different twist and following. 

In this case, I would need to find some private lender that does unconventional financing (higher interest rate) or I could use an FHA 203k loan.

To add value to the property, we undertook extensive renovations including the removal of over 40 yards of trash, installation of a new septic system and wall-hung boiler, and a new well pump.

Brandon Turner talked about it in his 2nd book, The book on real estate investing, he got a private money lender for one of his first deals from someone he went to church with.

This is a 3 story town home (detached) that shares a private sewage line with 7 other homes.

One big one is that scaling the lease option sale to a homeowner will attract both public regulatory scrutiny and private litigation, perhaps class action, once it reaches a certain threshold.  

You have zero control over the stock market, whereas when you do private lending, you have significantly higher control and contractually guaranteed return on your money.