I am looking to either add a protection period into the contract I currently use for wholesale deals or find a contract that already includes this. Something that simply states that the buyer I assign the contract over to cannot buy directly from the seller for x amount of days. Any advice will help, thanks!

@Jade Vaughn

In order for the buyer to go around you, the buyer and owner would had to have had a conversation. If so, then the owner will want to cancel the current contract with you and the reason may be something like, "I found another buyer at a higher price." But you can counter this by placing a lis-pendens on the property which will mandate a payment to you prior to the close of escrow. This business is built on trust and disclosures. You disclose to the seller that you are not the direct buyer but you are associated with them and you explain to the buyer that you have the property under contract and are looking to assign for a fee. Keep in mind that you can't force a seller to sell or a buyer to buy so you can only protect yourself by placing a lis-pendens on the property should the seller change their minds after the agreement. 

Hope that helps