As I recall, the staff requires the cores of each of the lower staves to be completed (bone, obsidian, blaze, etc.).
If I'm right about the progression, it goes something like this:
Iron-capped wooden wand
Gold capped greatwood wand (might be able to substitute silver here, not sure)
Thaumium-bossed silverwood wand ---- NOTE this is the last one that can be used in crafting with regular thaumcraft
Any staves up to and including silver-capped primal staff --- NOTE this is not used in crafting, so isn't nessecary for progression
I've not made it yet, but I think you might be able to jump to the ichorium capped, ichorcloth wrapped silverwood wand now (with no intermediaries), and that's the only one that has the power to give you thaumium-capped staves.