What type of atomizer are you trying to rebuild?
For a Genesis, you could go with SS Mesh, Cotton, Ekowool, SS Rope, Ceramic.
For a bottom fed, Cotton or Ekowool, perhaps Ceramic XC-116.
As a general rule, wick material is fairly cheap on amazon and e-bay. I generally
buy ekowool from lightning vapes on amazon.
If you want to try the XC-116 (It's really expensive, comparatively), you can
buy a foot of it here:
XC-116 Ceramic Wick - 12" Heat Cleaned
If you want to rebuild with cotton, check out some organic, unbleached cotton from your local CVS, Walgreens, Walmart, insert chain store here.
I think I bought my SS Mesh from e-bay, but it may have been amazon.