It costs a bit but is very worthwhile.If the tenants don't have bank accounts then find a bank near the property, open an account there and require them to make deposits directly into your bank account each month.

He has put down a deposit/offer on a parcel of land and now excepted the counter offer.

Give them authorization to direct deposit, and you're all set. 

--$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.