If ya gotta flip a coin between Port Orford Cedar or Sitka Spruce, remember that Sitka spruce exceeds POC in every category on engineering tables, including shear strength (shear forces are what cause arrows to shatter when they strike solid objects). The main advantage of POC is that it smells sooooo good when it breaks. The Spruce Goose was built from an airframe of Sitka Spruce, remember?
I get Sitka shafts from Hildebrand Arrow Shafts, they are the only manufacturer of the sitka shafts in the world at this time. 3Rivers doesn't sell their shafts grain matched, but Hildenbrand will do that for you.
Figure on using 125 grain points, sitka and cedar shafts are generally pretty light and 125 grain is plenty enough to make them front heavy. Thwackaddict asked what difference in weight the different shops had shown, average them out and pick the spine weight that matches the average. When you get the shafts, paint on any special colors you want, seal them with shellac, lacquer, tung oil, poly-you're-insane, or whatever you choose. Then fit on your points and the nocks and shoot them several times. If you are right handed, the arrows should "kick" the nock end out to the left. That's just fine. Means you can cut off an inch of arrow shaft and refit your points. Repeat as necessary until they fly straight off the bow, no wagging right or left. You may ignore the up and down action of the arrow for now, because that has to do with where you are nocking the arrow on the string. Once they come off the string straight, go ahead and fletch them out and they will fly dart straight with little wiggle waggle to slow them down. TA-DAH!