I'm having difficulty in finding a tool with which I can do a decent mockup of a vocal quartet. I want something that is fast to work with and it doesn't need to be that realistic as long as I can differentiate the soprano from the alto or the tenor from the bass. Couple of staccato and sustained vocals with one dynamic layer including full range of the soloists would be sufficient. Four patches, one for each singer. Couple of dynamic layers controllable with the modwheel would be a nice bonus.
Is there anything like this available? Preferably cheap.