3 Rivers and other suppliers have carbon test kits available so you don't end up buying a dozen shafts and find out they're the wrong spine. I think I remember one supplier that sold single shafts but I can't remember who it was. Most suppliers are very willing to offer guidance.
If I were starting out, I'd research the various brands and email the manufactures or suppliers for some quidance. At your draw weight, you'll most likely be in a higher spine shaft. However, each shooter and bow are an individual team. On this sight there are carbon spine charts that will guide you toward the right direction.