I posted my wooden Cyclone dust collector for my 2x4 challenge and I just got back from trying to find another good 2x4 to build a bucket for it to sit on. Sadly, neither Home Depot or Lowes had my favorite Orange 2x4's so I had to settle for a white one. I think the orange ones are Fir? either way, next time I see them in stock I really should pick up a few of them just to have on hand.
EDIT: so, Douglas Fir is the good stuff. generic Fir is lumped in with the white stuff. I even had a guy at a lumber yard try to tell me the orange stuff is the same as the white stuff, it just looses it's color after it's kiln dried. um... NO!