@Patricia MillerOne point of clarification that may help to simplify your planning: Both the Solo 401k and the SD IRA can purchase real property and use leverage in doing so.

I recognize this is probably a very complex question and my ignorance is trying to simplify it.

I'm a new wholesaler in Bay Area California and I was wondering if anyone has any advise on finding a simplified 1 page California purchase agreement? 

However, Fannie Mae guidelines instituted in late April 2017 state that:Student Loan Payment Calculation We are simplifying the options available to calculate the monthly payment amount for student loans.

Over time you could gain some control of the HOA and simplify the management as you expand.

To simplify, I used a single unit at $3,500 per month (same as the four units combined in your scenario).Bottom Line: start practicing finding a "purchase price" that makes a property profitable for you.Do not play with expenses and income numbers in order to make a property look good on paper.

That is the standard in the industry and simplifies book keeping. 

@Richard Rossi, if you're wanting to simplify things as you get closer to retirement and have to go the 1031 route you can't use it to purchase a reit.

Her and her husband are in their 70s, have owned the property for 25 years, and are looking to simplify their lives.  

Some states have a simplified process for small estates.