I had an interview with TCX, but it was a bit farsicle because it was arranged by MyTravel and I didn't go the "correct" route most applicants took. As for attire, I'd go smart. You wouldn't do any harm trying to wear colours that are vaguely the same as the uniform as well, because then recruiters get an idea of what you look like in their uniform.
Suffice to say I won't be going to my First Choice Interview in a pink jumpsuit though
Horgy