Salt Spring Island Seeds has some great barley for the
Wet West Coast.
I've talked with Dan before, and all his varieties overwinter here.
His Winter Barley does exceptionally well for me. I plant it before the end of Oct, and it just blows me away it does so well.
I too have the goal of a short season, over winter, Fukuoka style grain. I need one that can be planted before the end of Oct, and harvested before the end of May to suit my rain schedule. Fukuoka had one that he planted in Sep and harvested in April... but I've never seen one that matures that fast here

.... yet. A landrace is definitely a good idea.
I don't know if Salt Spring seeds ships south of the 49th (well, 48th and a little bit). If he doesn't, I might be able to post some of the barley seeds I saved last summer for sale on my etsy site. I have the winter barley, and the barley I saved from my landrace project. It's the 10% of my crop that matured the earliest.
rareseeds has some grain as well, but I don't know if they have any short season one. It seems to me they are a bit too far south for the grains to be much use where I am.