California Purchase Contract for Flipping Houses

I live in northern California and have a question about the purchase contract. Before flipping a property to another investor, you must have that property under contract. Do we have to use the 8 page C.A.R. California Residential Purchase Agreement to put the house under contract or can we use a shorter, modified purchase agreement? I have a 3 page contract that includes the necessary clauses that will allow you to back out of the deal if you can’t find a buyer. HELP!!

I use a simple 2 page contract, I got it out of the book “Real Estate on Steroids” by Jackie Lange I tweaked the contract some to fit my situation better,.
It also has a simple “Assignment of Contract” I have used many times.
U can find the book on Amazon for a few buks.