i would recommend bill ammons, bob fitzgerald, mike williams of radio-x tuners, joseph chow of component plus usa, stephen sank of talking dog transducers, stereo surgeon. bob f and bill a do their work on the side, so turn-around may be longer.
i would awoid ed hanlon of antenna performance, as he is a bit on the psychotic side, and will tear you a new one, if you ask any questions about the work. he has accused me (and others) of "trying to steal his secrets so i could diy". as if i couldn't awreddy diy w/all the info on the tic, if i had a mind to do so!

likely, he's yust hiding the fact that he doesn't know squat about modding tunas - he subs all his work out. so, why not yust go directly to the source instead of paying a middle-man? i dunno for sure, but i suspect he is now using these guys (he has used don scott and stereo surgeons in the past.):
http://www.approvedaudioservice.com/ speaking of don scott, he's another one to awoid. he says he aligns tunas "by ear". this is a physical impossibility - you need good test equipment to properly service and align tunas. i know several folks whose tunas worked worse, or not at all, after don touched them...
if you want adwice re: specific tunas, i am happy to answer questions, i have listened to a lot, and presently own ~35... yikes! also, ask questions on the tic's yahoo forum.
re: the sony xdr f1-hd, i have found it to be the best sounding tuna i own, but
only on stations other-wise unlistenable due to poor reception/noise. and, only when used w/a tube buffer stage; otherwise the sound is too fatiguing, even on non-hd stations... my better non-hd tunas beat the sony f1-hd's sonics on decent signals.
hth,
doug s.