I started the old-fashioned way, by making sure my credit/income was good and I applied for loans with banks and mortgage brokers. 

First American Insurance 

Edit: The insurance company was Ranchers and Farmers run by American Bankers Ins Company in Miami Florida. 

So the modern estate tax impacts less than two-tenths of 1 percent (0.02%) of American’s, unless you live in a state like Oregon.

In 2011-13 it was way worse, I lived in the American Can Building -  Considering the lack of inventory elsewhere in Cincy it should turn around. 

And we do the verifications the old fashion way of actually calling the employers and landlords to get the info straight from the source. 

@Yacov Barboigetting mortgage as a foreign investor from American Banks is possible. but interest rate is not going to be great, not close to what you are familiar with in Israel and Germany.if the numbers on specific deals work I do see allot of foreign investors using leverage.

The IRA is handled and reported in the same fashion, but instead of just focusing on the public exchanges, they can document an IRA investment into shares of privately held stock, crowdfunds, private mortgage notes and the like. 

So yes, you could incrementally "move" the Roth IRA to the Solo 401(k) in the fashion you describe.  

I can recommend Texas American Title / Patten Law Firm in Irving TX.