Although in the last couple deals most have come out as 506C deals where only accredited investors are allowed, there are still 506B syndications where you can be a sophisticated investor (self proclaimed) so you don't have to be accredited.

Note that a truly self-directed Solo 401k would be exempt from UBIT on leveraged real estate. 

Wife and I are both self-employed so acquiring a traditional mortgage is challenging based on our "on paper" income.

I am proficient in investing and confident in earning 7-10% returns in the market over the next decade or two.

if so she should be self managing and saving herself the 6-10% on rents. 

I own a duplex with my husband and have been self managing the rentals (one is MTR and one is LTR) under my LLC.

You can also just do a self-directed IRA and start making your money work better for what you are doing. 

Overcoming Common Financing HurdlesMortgage brokers excel at tackling challenges that often derail new investors:Low Down Payments: Brokers can find lenders offering low or no-down-payment loans, ideal for new investors with limited capital.Complex Income Streams: If you’re self-employed or have variable income, brokers can identify lenders that accept alternative documentation.Competitive Rates: Brokers have the leverage to negotiate better rates and fees, saving you thousands over the life of your loan.Pro Tip: Communicate your investment goals clearly with your broker so they can tailor their search to your needs, whether it’s a short-term fix-and-flip loan or a long-term rental property mortgage.3.

Their income is also all self-employed and social security benefits.

I am a self-entrepreneur and know the importance of office space.