Where can I find a 'Letter of Intent' to take control of a property I'm interested in wholesaling?

If they are due a surplus, they are probably already getting at least a dozen letters so you would have to really stand out. 

I wrote a letter outlining who our company was and what we wanted to do with the property.

You first deliver to them a Letter of Intent, usually a non-binding document stating your intention to purchase the property for a certain price, type of financing and other criteria specific to this deal.You want to have the actual income and expenses to analyze before you make an offer.  

My last call was from a property owner that is ready to sell a property because she can't visit the property as often as she'd like.She told me that I am the only one out of all the letters she's received that called her back or even answered the phone.

You would just need an appraisal release letter from your current lender and confirmation from the new lender that the appraisal is acceptable, per their requirements. 

Best to follow your survey to the letter.

If so, what do you use as your rejection reason on their adverse action letter?

You could be stuck with a balloon payment, sellers usually don't give buyers 15-30 years to pay off their note.

a yellow letter as i would a potential property deal and is their a right or wrong way to go about addressing the potential cash buyer if he or she were interested in joining my buyers list?