I did find some background on him and it seems like he's been mainly focused on stocks, etc, right?

Home Depot in stock cabinets are just fine for a rental.

My lease stipulates that the tenants are to maintain the yard.

My future plans for the company would be to use the knowledge, skills and contacts acquired to develop/Remodel/maintain my own real estate investments.

His attorney has suggested we secure the loan with a pledge of stock in his company, but I'm concerned this may come across as a partnership and trigger UBIT.

As the years past, we had all of our money in stocks which we lost a lot in 2008.

Its much like looking at stocks and comparing how well each has done and looking at its 10 year history, like Benjamin Graham taught.

Plus you'd have access to 401k funds to invest in things that return better and less risky returns than the stock market.  

thanks everyone I think I might have to do the cash for keys but now I have to figure out a date to do it and the place is well maintained (surprisingly).

@Getachew Hundera,Another source of private lenders is anyone with whom you establish a personal relationship (prerequisite to private lending per the SEC) who would consider investing in your deal.Essentially, it could be anyone who is nervous about the risk and volatility of the stock or other markets and is looking for a safer investment secured by real property.Learn how to attract and engage private lenders other than your family and your current friends and associates.