Zinc is invaluable for this purpose, and really can't be replaced by that much (that you can acquire as easily). Ebay is an acceptable source, there's some zinc sellers that sells to the whole world up there I think.
But please develop your own method of reduction. You don't actually need as much water as people tell you (less water = faster reaction), a magnetic stirrer, and you certainly don't need to do messy naphtha pulls to get the freebase out of the water. Just filter it (please use REAL filters), and you'll get your spice converted AND cleaned from lipids! Can it get any better!?
There's a clear difference between what I say I do and what I actually do perform.