Afraid I'm very late to this thread, but in case the OP is still following: since you have some EOS lenses, you might consider an EOS Elan (EOS 100). It's astonishingly quiet, and the sound is mostly low-pitched and very unobtrusive. Several of the other low-to-mid-range EOS bodies are in the same league. Best of all is that Elans are dirt cheap these days, so it would cost you next to nothing to try. The one thing to watch out for is that on many of them the grip has become sticky. I just put electrical tape over mine - no reason to be fancy with it.