There is no profile of the typical real estate investor that lends but if I had to put the two categories, it's investors that are very seasoned that still want to be part of the game yet may not want to hustle like they did when they were younger and the future was uncertain and W2 corporate investors that have large self directed IRA and solo 401ks to lend off of. 

One investor comes to mind, we set up his Checkbook IRA with about the same amount you have for your son, he invested in tax liens and was able to grow it pretty rapidly.

I spoke with a financial advisor and I am putting about 20% of my income into a variety of accounts; 401k, Roth IRA, 529, and general savings.

I found the deal, I bring the investor, and I bring the labor; the investor bought and paid for the whole deal in 1st position via Self Directed IRA. 

If you already have a Roth IRA, and have success in a particular asset class such as real estate, then moving the Roth to a self-directed Roth IRA capable of being invested in real estate can make a lot of sense. 

Using your IRA to lend to yourself will be considered prohibited transaction by the IRS and will disqualify your IRA resulting in sever penalties. 

Sourcing Funds (outside investors, institutional funds, self-directed IRAs, etc)Feel free to connect if you want to ask any questions.

Lucas, I am investing with my IRA so I will have to use a property manager anyway.

They always ask for something (however small) and it can feel like an 11th hour scramble to find that 2015 Roth IRA statement

As far as the money to pay for the construction, together they have roughly a million dollars in 401k/IRA (Note: My dad will be 59 1/2 in February and my mom in November).