First, welcome to FTE, and the Oregon Chapter. I cannot help you with a shop in your area because I'm 150 miles east of Portland, BUT your best bet is to call Transmission Exchange in Portland. I've been buying quality tranny parts, and rebuilt trannys from them for over 40 years. They are a great company to work with and could steer you to a local shop that they work with. Link: Rebuilt Transmissions Transmission Parts
If you would like to join the Oregon Chapter just click on the link at the top of the forum, follow the instructions, and I'll approve you.