Ditto what Mac said. As a DSM you look for neither fame nor fortune, if you are after either of those two things then you are definitely on the wrong side of the production desk! As such you won't meet any famous DSMs. You will however find some very well-known (within the industry), respected, renowned DSMs.
I guess you are in the UK (because of the use of the term DSM and your post on another forum I've seen) so I would start looking to speak to DSMs working at the NT (i.e Royal National Theatre), RSC (i.e. Royal Shakespeare Company) and then regionals like Bristol Old Vic, Donmar, Royal Exchange etc. Most of the people who word in these circles are very well known in the industry. Depending on what particular style your looking into however you might also want to have a look at West-End Musicals (Mamma Mia, Lion King, WWRY, Evita, Marry Poppins etc.), Operas (WNO, ENO etc.) or Ballet/ Dance (Rambert, ENB). If you PM me I will be able to forward some names onto you BUT if you feel like finding out some more on your own contact these companies yourself and I'm sure they will not only forward you onto the correct people but they'll also be very helpful!
Sam