I’d say the most important thing is finding the source.  

You won't figure this out from Costar or Zillow or most other data sources. 

You can search online for companies in your area that lend that way.But I'm guessing if you talked to the people around you, showed them what real estate investing can do, and offered a good enough return, you could pool money from multiple family and friend sources to make it happen.Most people aren't sitting on tens of thousands of dollars, but most people have 401ks or IRAs and if they trust you, and you are trustworthy, you can teach them how to pull loans on their retirement accounts that don't penalize them, and give you access to more money than you realize you had access to.Probably start there.

Hands down the best source of information.

For ultimate protection consider a Series LLC, each note purchased under a separate series of the LLC so that their is no risk to other assets; any liability stays solely with each note.

Look at the source of the funds used to make each payment. 

I am a sole propriator LLC so I'm guessing that I'd need to switch to an S-corp or something like that to hopefully qualify for arms length.?

Banks are very familiar with mobile home parks and how to structure loans.The top sources of mobile home park lending are:1) Seller financing by the moms and pops.2) Bank loans (typically smaller banks in the town the park is located in).3) CMBS Conduit lenders (on deals where the loan is $1 million and more).4) Fannie Mae/Freddie Mac "agency" debt (on loans of $2 million and more).You rarely hear of a mobile home park deal that can't get financing today because banks love the industry and it's incredibly small default rates.

It’s a problem with your source of funds

@Danny Jimenez Typically you pick sources that research such information and either pay for it or find in free formats.