Hey Petie81!
I just bought MIDI Quest 10 XL from Soundquest (
www.squest.com) and its a great librarian/editor for the Virus C series. MIDI Quest 10 XL supports over 700 instruments I think.
You can buy Uni Quest 10, which is a limited version of MIDI Quest that lets you pick the synth you want to use upon install and limits you to that one alone. You can upgrade from Uni Quest to MIDI Quest without penalty.
The product works on PC and Mac.
I hope this helps you out.
Cheers!
-Alex