9x12 is a little small to contact, but some people love more "intimate" small contact prints. you can just use a lamp for that, no enlarger needed at all
It should be easy enough to avoid digi stuff. Almost any serious lab will print 4x5" and most will use glass carriers. The slightly smaller negs should be no problem surely? There are at least a couple of film labs in Paris, but everywhere should have a few (I do my own so don't have a list). If you get stuck you could e-mail Fotoimpex to ask about their "Labo" services.