Welcome nuttallii (clever name!), I also garden near Seattle, but I think Portland has the nicest climate in the country- lucky you!
I plant anything that strikes my fancy, I do make an effort to include natives, just yesterday I planted some bunchberry and cascade penstemon. I got them a few months ago from a huge yearly native plant sale put on by the local conservation district, which is the absolute best source here for really inexpensive native plants. They get them in quantity, many are bare root in big bundles like they use for reforestation projects. The reason I am telling you this is they sell Pacific Dogwoods.
Maybe there is something like that near you?
On the other hand, it is especially fun to grow things yourself from seed. I have some Sourwood saplings I grew from seed. I also have two I got from a local nursery before that, that had been grown from cuttings. It turns out that is a really bad idea because they don't want to grow up, they want to grow sideways!
I tried some Cornus controversa 'variegata' cuttings. Failed. I finally found a sapling to buy, and it will soon be big enough to try again from my own tree. C. controversa 'variegata' is supposed to be particularly difficult to propagate, hopefully the native one is easier. Speaking of which, I have some Hormex #8 rooting hormone, I might get some of the stronger strength for that project. Have you ever tried it or tried the gel?