Nope, not many folk around with the skills to properly tune M3.8, infact theres not many folk around with the skills to properly tune any car.
Most "tuners" rely on bought in maps which is why you end up with all this "stage1, stage 2, Stage 3" rubbish, because instead of tuning the car as provided, they're using prewritten maps and modifying the car to suit the maps that are available to them. Ofcourse, thats fine if you have a common car and are prepared to follow those pre-set mods, however something like the A4 where those pre-set mods dont really exist you find theres nothing actually available.
MRC are closer to you and are fairly well respected in tuning ME7 stuff, but they made a right hash of Marks M3.8 ECU in his 1.8T, so caution advised there.