@Chris Thomas , you may have some luck with sending a letter via snail mail in hopes they set up a forwarding address.

@Alexander Carrasco, I was planning on pulling together personal funds and couple of the people I work with to come up with the down payment then for financing I was going to ask the owner to carry back the rest with roughly a five year balloon.

Go driving around the neighborhood and find some places that you're interested in and hand write a few letters to them to get you started.

A personal loan with a balloon, and then we just split the profits with him?

If you don't find anything and you think that offering to buy a Rental is a way to go, then, make up a proposal letter to send to each owner that has a property that would fit your needs.

I've sent out 4000 post cards and 2000 yellow letters in the last 6-8 weeks and I've received 40-50 calls but only spoke to 5 unmotivated people after the call center screened them.  

They should provide you with a loan letter that states their the average time it will take to close a loan and you can include a copy of that with your offers.  

Request they give you a Pre-approval letter with the loan amount you qualify for so you will know how much of a house you can afford and the letter is good for 90 days and can be renewed.

My intentions are to both send mailer letters and to cold call the mobile home park owners.

This will start with a letter to all, stating the new ownership, any new or newly enforced rules(no smoking, cleaning up after dogs, etc.), and mentioning that they have until a certain day to start paying the rent or move on.