You're much better off doing it yourself. You won't have to worry about overheating by the use of powered equipment by some 'pros'.
French carbons sharpen very easily. Have a look at BDL's contributions about stones. IIRC he mentioned oil stones as well as a possible option with these blades. Have no experience with them, though. My experience is limited to Japanese waterstones and Arkansas, and both work great with soft carbon. That being said, if you've no other steel types to sharpen, the Japanese are somewhat an overkill, I guess.
In general I wouldn't look for an extremely refined edge as the scratch resistance of this steel is relatively low. No higher grit than J2000-3000, except for deburring perhaps. And with a slicer some prefer a much lower grit because of the resulting toothy edge, e.g. J1000 and than stropping on split leather -- or cardboard, denim, newspaper or whatever.