--$200 for deposits on the first few houses I put under contract.--$300 Networking.

He is willing to offer 2x the security deposit and has about $8K in his bank account. 

Then they ask people to wire them a deposit and they can move in in a week.

I have a home equity loan from many years ago with zero balance that's still active but I'm afraid if I use that for the necessary upgrades to my current home to make it rent ready and for the deposit on the new home that it will ding my credit when purchasing the new home.

I take a low interest personal loan for $5k and deposit in a checking account and set up EFT payments.

A letter from Billy doe not really prove this so perhaps a bank statement showing deposit are needed.  

In the past it has been understood that you can't charge a pet deposit but landlords would just amortize the pet deposit along with the monthly rent to get around the law.

If they have not held their job long or if they don't have rental history, I'd require a co-signer or higher deposit.  

Florida, like most everywhere, is an all cash scenario at the time of purchase or with a 5% deposit and the balance due the next morning. 

In addition, the deposit on the property is typically 5% - 10%, I have read numerous forums, etc. that proclaim that wholesaling is an excellent way to get started as a new investor with minimal capital available.