I always liked Chundoo!!! Actually Sitka Spuce, and Lodgepole Pine, are the same thing. Kinda like everything that holds its needles is an Evergreen, but most folks just call them "pines" lol. I've had a few dozen Chundoo arrows over the last 20 years or so, and still have 4, from the last dozen Joe Skipp made for me about 10 years ago in my stumping bucket. As for straightness, they leave a lot to be desired! However, as for durability, I find them up there with ash & hickory, only much lighter!!! I have bounced them off of trees & rocks, and returned them to my quiver after passing inspection! The 4 left in my bucket, look like corkscrews, but they still fly straight & true!!!
As for Spine... I agree with the others. The 5# rule is pretty simple AND accurate, when it comes to wood arrows. Shorten or lengthen 1" will increase or decrease spine 5#.
Much simpler than carbons, in this old fart's opinion!