Need advice on getting mortgage with no income

Me, my brother and father-in-law are just getting started in REI. We have two offers out on properties that we will be buying with cash. Our strategy is to purchase the home cash, rehab, then refinance them at the ARV.

The problem we are running into is my family member (the one providing the cash) does not have any income other than social security.  He has liquid worth and a fully paid for residence, but no stream of income.

The bank would not give him a pre-qualification - any advice on options for long term financing?  If we started a legal entity, would a local bank be more inclined to lend to us if we have a solid business plan and present full analysis on the investments?

Side note- there are 3 of us, however I currently have two mortgages under my name, and my brother has 1, so we may not qualify for much and we'll be close to maxing out our DTI ratio.