But all returns go tax-sheltered to the IRA.A Rollover as Business Startup (ROBS) plan will be the program to evaluate.  

@Joe DaikerThe ROBS 401k (rollover business startup) allows for flipping real estate through a real-estate operating company. 

What I do know is I have a settlement coming from a roll over car accident that was caused by the other driver.

Personally, I time all of my leases to roll over in June so I am in the middle of the busy student housing season.

He is paying the loan back with post-tax dollars, so there is the hidden cost of whatever his tax rate is.The better option would be for him to rollover all or part of that old employer 401k to a self directed IRA.  

From there, they will likely deliver those documents to you, help you setup a bank account for the trust, and support you in any transfers or rollovers of existing retirement funds into the new Solo 401k.

The business sets up a profit sharing plan or 401k that you can rollover tax-deferred retirement savings into such as from an IRA or old 401k.  

I do have a partner that wants to buy more SFH's and I on my own want to roll over my IRA to a SDIRA and do some flips in the area.

With the IRS approved Solo 401(k) Plan, roll over your existing IRA or 401(k) plan funds tax-free into a new Solo 401(k) Plan and use those funds to make tax-deferred investments, such as real estate, while also gaining the ability to borrow up to $50,000 as well as make annual plan contributions up to $59,000 – almost 10 times the amount of an IRA."

@Skip GilliamWhile not for everybody, you may want to look at the Rollover as Business Start up (ROBS) if you are looking to quit your corporate job.