[eskimo]

I bet you could get away with basswood. I recommend epoxy sealing it as it tends to have issues from time to time. If you had red cedar you would most likely want to epoxy seal that anyway.

Basswood is great.. but I've never used such a inconsistent species of wood before. I've milled some and ended up with squares that seemed as heavy as maple and I've milled some and ended up with squares that were as light and soft as balsa.

edit: Didn't see that you had EWP - me thinks that'll work perfect.