Finding the applicable exemption set is not as easy as picking the exemptions of the state in which you are currently residing. You can choose the exemptions of the state in which you have been residing if you have been there for two years. If you did not live in either Oregon or Washington for the last two years, you use the exemptions of the state where you lived the majority of the six months prior to the two year period. If neither of these rules result in an applicable set of exemptions, you get to use the federal exemptions.
If the Oregon exemptions are applicable, you will get to use only the state exemptions. If the Washington exemptions are applicable, you will get to choose whether to use the Washington exemptions or the federal exemptions.