No you do not have to research OR law on this. The CA agreement that I have given you is 90% good to go. What you will find is the 10% change lies in changing any forum selection clause and choice of law clause. This is why I told you you may want to put that disputes have to be filed in OR and OR law should apply in deciding them.
I cited the pointer for you at the "read this" link just so you would know how OR governmental bodies view employment and independent contractor relationships; which is really in substance the same as how the IRS and other states view it. Governments want to make sure they collect employment taxes and workers comp premiums from employers who try to outsource jobs merely to circumvent those burdens. In other words "it is a substance over form" type of argument. So, this was just an FYI for you that has little or no bearing on how the IC agreement would be drafted. If you were asking for a real estate document, things would be different, and you would want to try to use OR real estate forms to do a deal, for example.
That said, unless you want to pay a law firm $250-$300 per hour to do it, you will need to read, mix and match, and modify, the clauses that suit your needs from the sample OR and CA agreements that I cited for you.
If you want me to this for under JA's premium services offer, please let me know. The same cite terms and conditions would apply and you would be using the draft that I create for you at your own risk and if you want legal advice you would need to consult a local lawyer in person. The fee that I would recommend to JA would be $300.00 and you would have the agreement ready with in 36 hours. It would include up to 3 telephone calls to make sure we get the agreement to your liking with custom clauses.