My barn is board-and-batten, random pattern. I used Ash for the siding (located in NW Ohio) due to the poor market for ash trees.
From what I've read, and what Tom stated, the new TA Schmid mills tilt the sawing head, leaving the cants flat on the mill bed.
RLHERRON, nice looking shop. You look pretty far down the road, I think one of the secrets to a good shingle job is the ability for the shingles to breathe on both sides, as TexasTimbers stated, you could use a thin sliced board for siding, or "board fashion" shingles.
I'll post some additional pics later on.