Yes, the sound are available online. A Google search would have pointed you this page for sure:http://homepages.abdn.ac.uk/mth192/pages/html/dx7.html
Don't know if a sequencer would work, but a patch editor/librairian would do. Try Midi Ox.
-Roland JX3P+PG200, D50+PG1000, Juno 106, MKS50/70, JP8080, U220, MVS1, MSE1, MDC1, MOC1, TR707
-Korg M1R/M3R, MicroKorg, Micro X, Kaossilator, Monotron X3
-Yamaha DX7, TX816, Motif Rack
-Future Retro 777, DSI Mopho, EMU Proteus FX