I think instead of a zeta mat pack, maybe have an omega mat pack. Zeta mats are way more plentiful than omega mats, at least according to my experience. Right know I could apply 2 zetas except I need more omegas with no real way to get them. The omega events drop 1 mat each time. As far as farming them from nodes, I have seen a grand total of 2 omega mat drop from a node in the entire life of the game. Aside from needing them for zetas, you also need many of them for maxing out non-zeta skills as well...usually 5 mats per skill. Add those to the 13-20 you need for a zeta skill, you're way, way behind the 8-ball.