I agree with Brian, but that said, I've had good experience with Modernage for straightforward development of TMX, and I know they'll take mail order, and they do a decent volume of B&W for commercial purposes (headshots, advertising, weddings, etc.). They will also give you multiple contact sheets at no extra charge on those rolls where your exposure is inconsistent. Locations at www.modernage.com.
Whichever you choose, you should send some test rolls first. They'll do fractional pushes and pulls and are very consistent, so you could even work out what to ask for for N+ and N- development.
dr5, known mostly for their B&W reversal process, will also develop B&W negs by inspection--develop only, no contacts. I've never used them for this service, but I would trust them to get it right. I think he just moved back to the West Coast. Info at www.dr5.com.