I think from your description of the 06's sound German tubes would be a good match for their air and speed. I think another good match would be the Cifte/Mazda's made in France.
I can report zero ill effects though with the DF96's
These are two pages from a site I use as a reference. GG is right going by this both types are the same
I did check quite some time ago with Shikada San and he gave the OK on using the DF96's as a direct slot in replacement for the 05. I would imagine the 06 would be fine as well though I will message him and ask!