I have the Corsair K70 and I use it for osu!, it's great. Keep in mind that these two keyboards are practically the same, they're just standard keyboards with red switches. Corsair has custom keycaps with a different texture to them if you play FPSs, but that's not needed for osu!. It also comes with a wrist rest (I always use it, it helps tremedously). The CM storm trigger Z has other features like macros that aren't needed for osu, so when you strip them both down to the bare nessecities, they're practically the same keyboard. It all boils down to personal preference, which do you like more, the red backlight or the white? If you want to save more money, go with the CM Storm Trigger Z (there's not much of a difference to the price either way).
Hope I helped.
