Wholesaling deal with owner wants a bank financed offer.

[Bernard Sanga]

Hello, 

I am trying to wholesale a deal with an owner who will accept a bank-financed offer. He does not want to owner-financed and is interested only in getting the highest price he can for the deal. It is a new home built in 2019 so it will pass 4 point inspections with no problems.
My question is - how do you structure the contract in this case? Do you assign or double close? Does it matter?
Do you get your assignment fee only when my end buyer closes on it? I am worried about the longer closing times and if the end buyer then decides to not close the deal.
Looking for insights on how to best handle this.