This is good news (great responses too). That's my druthers for the moment, basically track down a CSX or Chessie unit and then convert to sound later on.
Thanks for responding. I was considering, at least for now, a Silver GP40-2 either in Chessie or CSX scheme where Atlas carries both choices in the Silver series.
Pretty much what the header says; I've tried net-searching to find out if various Atlas HO Silver series diesels, being nominally DCC-ready, are also adapted to allow sound decoder and speaker installation, and also have holes pre-punched somewhere. No luck so far.
More directly I could buy...