I'd pass on the Ecto-Ichi being their vehicle, however. Have them mention
that it existed, sure, but it was packed with so many gee-whiz untested prototype hardware the Ghostbusters never used again (and in some cases never used while they had it!) that important parts started breaking and rotting away long before Kenji gets into contact with GBI's franchising office, which causes them to use something more sane for their Ectomobile (as Ghostbusting technology will be far more mature at that point, so they'll know what actually works and what's practical). Edit: I just read that the Ecto-Ichi got squished by a Gojira projection, so that's a moot point anyway.
Though I can't help but imagine the Japanese team's flight suits being in multiple colors, like they're some super sentai group (Their primary color with white trim, perhaps? You did a pretty good pic of yourself wearing what the second in command would wear
if you go that route).
And now I'm imagining the team spending some of their off-time just goofing around in their flight suits, doing super sentai team poses.