Bones are incredibly easy to find. Many butchers would be happy to keep some aside for you -- for a small fee in most cases, but really just a couple bucks.
Antlers would be a little more difficult, but considering it either is or soon will be deer season in many areas, that makes things a little easier. However, if you're looking for antler long enough to make into a long wand, you may be a bit hard-pressed to find what you seek. That said, I'd suggest calling some game processors (people who will clean and butcher deer, elk, etc., for a fee) and ask their terms.
You may be surprised.
And tell them you're wanting to dry and preserve the bone(s) for craft projects. Bone is a very common material for knife handles, so that will seem far from odd to any of them. And ask what the best way is -- or there's always the internet.