Is it possible in Sibelius to create a new Staff Type, that during playback using the computer soundcard/MIDI sounds (not loading VD1 or VD2 sounds), can produce two sounds, for example: Vibraphone and Crash [Suspended] Cymbal on a single staff?

  TS

It depends on your sound source. If your playback device (your soundcard I assume) will allow you to send program changes, you'd have to enter that into sibelius as such:

~P'X' ('X' equals the program number (suspended cymbal) you wish to change to). for example...if you wanted to switch to program number 13, you'd enter this as a technique text into Sibelius:
~P13

Secondly, you'd create a staff type change in Sibelius by going to Create>Other>Staff Type Change>Percussion, and selecting the staff type that uses the cymbal notation you desire.

When the cymbal part is done, change the staff type back to Pitched>5 lines, and do another program change back to your Vibraphone (or whatever) patch.

I'm not sure if General MIDI soundcards are accustomed to carrying out these types of commands. You'd probably need to check with the manufacturer.