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 6+106, MKS50, JP8080, U220, MVS1, MDC1, MSE1, RS09, TR-707
-Korg Poly61M, M3R, MicroKorg, Kaossilator/Pro, Monotron X3
-Yamaha DX7, TX616, TX81Z
-Crumar Performer, DSI Mopho, SCI Prophet 2002, Simmons SDS7