Just want to make a comment. The website at Bonsai Northwest is not a good indication of the great things in store when you visit. There are a large number of bonsai and pre-bonsai trees of many species. Also, there’s a nice selection of pots, soil and supplies.
It seems they’re just too busy with the trees to spend much time on the internet. Be sure to check them out.
(I have no affiliation. I’m just a satisfied customer.)
The Pacific Bonsai Museum and Elandan Gardens are not to be missed!
For tropical trees you might try:
Asia Pacific Gardening
19122 84th Ave S
Kent, WA 98032