For rauch malt, freshness is the key! I have brewed quite a few rauch beers at home, and found the best thing to do was call the homebrew shop a week ahead and ask him to order me some rauch. The smoke character dissipates quite a bit over time.
I don't know of any other sources of beechwood smoked malt, although Briess is now doing a cherrywood smoked malt that I have yet to try...it smells delish!!