For years I've worked with Dupon in Paris on processing and lately gallery prints.
http://www.dupon.com/
They are excellent and upfront and it's not out of the ordinary to ship back and forth to a great lab.
I've also worked with Lamont in NY for 10 years which is excellent, though also send a guide print.
http://laumont.com/Atelier Lumiere in Paris has a great reputation worldwide, (though I favor Dupon because I know the owner and he's truly wonderful), but a lot of heavyweights like Paolo Roversi and Peter Lindberg print there.
http://www.atelierlumiere.fr/Good luck
IMO
BC