Vicar in a Tutu

Here's a tricky conundrum for some of you clever modders to get your head around. I have an Aerodyne Jazz bass (100% passive) that I will be replacing ALL electronics from as soon as I've got my circuit figured out, and when I can therefore order the required components. [u]Shopping list so far includes:[/u] Seymour Duncan Quarter Pound P/J Bass Set Seymour Duncan STC-2P Preamp Gotoh 18V Double Battery Box [b]??? mystery switch ???[/b] I will need to rout for the preamp and battery box, and drill through for the switch. [b]The aim:[/b] I want to install a 3-way switch (preferably a round rocker in the style of the one pictured below) that will allow me to select: [b]9V Active[/b] (2 batteries in parallel) [b]Passive[/b] (bypass preamp + batteries) [b]18V Active[/b] (2 batteries in series) This is an easy project if I use two switches as in the diagram. However, I am going for simplicity and aesthetics, surely it must be possible with only one? I assume I will need at least an 8 pin on/on/on, can anybody help with sourcing this elusive switch and a wiring diagram? [color=#141414][font=verdana, geneva, lucida,]Here is the preamp circuit for reference:[/font][/color] [color=#141414][font=verdana, geneva, lucida,][/font][/color] Thanks in advance.