Pappy, did you end up purchasing the iBooks from my place or were we still awaiting their arrival? I heard my boss this morning bitching about Ingram-Micro's failure to keep us stocked with product.
Anyway, you can find some hacks to change that volume up/down blip or you can change it in the sound prefs and then it will make the error noise you specified:
(Note that you can disable the sound, too.)