What's best next to a cash offer?

[Tyler Stephens]

I am almost done reading J Scott's The Book on Flipping Houses, and in it he mentions that you can't technically say you can make a cash offer unless you literally have the cash in your account ready to spend, and brokers will usually ask you to prove it. 

I don't quite have cash to offer, but I do have a private lender who will pay for the property in cash (either give the money to me and I pay, or write a check directly to the seller (If anyone has any advice on which way to go on this point, that would be well-received also)).

My question is, since I can't technically call that a cash offer, would it be beneficial to show some kind of promise to lend from my lender and a financial statement showing funds are available in his name? Would that help to get me better consideration than someone with more traditional financing?