Also, does anyone know any closing agents/ RE attorneys in South Florida that handle double closings, or simultaneous closings?

Let's just say we lent each other $200-300K simultaneously on an unsecured basis, or allocated a similar amount to fund 70% of ARV on rehabs as they're sourced?      

Not sure how close and trusting you are with your brother-in-law thus, you can always secure an option on the property for lump sum or percentage of the sale if your tie the property up and conduct a dry escrow/simultaneous close.

I like that you interviewed/hired your PM simultaneously with taking ownership.

Simultaneously I'd talk to a local commerical bank and say 'I have a duplex on Staten Island that I want to buy but I need a few bucks to buy out my relative.

Conversely, there would be a margin, which would become apparent to the end buyer as a simultaneous closing wouldn't work as I know it, with owner financing.

I have only done simultaneous closings with all cash sales and never with one side using a mortgage for funding.

Enrique provides 210k plus closing costs, and allows 30 days or more for Jeff to close his loan to purchase the property at 300k.Transactional Funding is related to or also known as funding back to back closes, flash funding, double closes, simultaneous closes, double escrows.Enrique Barrios, 818-915-2543 ph, Transactional Funding Lender, Hard Money Lender, Real Estate Investor, Los Angeles, CA.

I think I would be too thinned out if I followed both paths simultaneously. 

Build rental agreement (I believe 3 and 4 should be worked simultaneously, once i find a good property I want to be ready to rent it.)5.