Currently, I own my primary home and a rental in San Antonio, TX. 

They got me the loan in two and a half weeks.

We have another park with a free space rent manager and as we have raised the rents he continues to live there for free. 

We can also lend to both individuals and LLCs.I'd be happy to share my experience as both an investor and as a lender.

Right now the only utility at the garage is power so basically I am starting with a frame and a roof. 

As both an investor and a mortgage broker who has personally used both options, I can say there are benefits to each.It ultimately comes down to comparing the two side by side based on your specific situation.

And a few from 0% interest for a year credit card loans too.

I have several vehicles and lots of stuff in general and a wife that would not be ok with a duplex.  

In addition to conventional loans and FHA loans, if either you or your wife are veterans, the VA also has a rehab program.I'd be happy to discuss my rehab experience both as an investor and as a mortgage broker, and at least help you think through your options. 

We have modified many seller financed notes over the years (with input from the servicer and a qualified attorney as mentioned by others).