I'm back with more info.
Turns out they use Kodak chemistry in their Noritsu film machine, after all.
The guy couldn't tell me exactly the Kodak codes for their minilab, but told me that they use replenished chemistry, so I'll also need a starter, etc.
We finally agreed that perhaps it would be the best to get a 1 liter each (developer, bleach, fix and stabilizer) of already mixed chemistry, directly from the machine tanks No problems with activating the chemistry (no starter needed), and no problems with dilutions.
I think that's the most practical way to do it, and we'll probably take that route.
Now I just have to try to find color negative film in 4x5 format, which is not an easy thing these days....