Hello, a friend gave me a bag of needles, but they'll quickly be used up. They're the straight needles which just slide up into the hole there and you screw them in. He said that because we live in Phoenix, AZ, that we could get some cactus needles and use those, but I would rather buy needles which have been recommended specifically for this by a dealer. Can I buy steel ones, or maybe the bamboo ones for a softer sound? If so, I'd appreciate an online resource where I can order a batch of either kind. Thanks a lot. Matthew