Shadow Star and the Snowstar that Xiadias mentioned in the post you quoted are it for named shuriken until the level 12. At that point you can use Green Steel or Alchemical (ML12) but those you would need to have raided for on a higher level character. The next named one is The Morning Star, available at level 14, and after that it's ML16 for Cormyrian Spelltouched Shuriken from Eveningstar Challenges.
Personally I liked the Snowstar better than the Shadow Star, but it probably is only a moderate improvement.
Cannith Crafting might help filling in the gaps, but it takes a bit of investment to get to good skill levels in it.