The Double Edge guitars have an A/B switcher in them already, if you just want to use a mono cable.
I know Kevan has been working diligently to source a stereo barrel jack, which would be a nicer option than the two jacks.
Raffel: There's probably tons of information elsewhere in the site... if you do a search for "2027", you'll probably get a lot of info on what rigs people are using. I've got a Parker, and i send my magnetic signal to a GT-6 and then into whatever amp or PA is handy. My piezo signal goes into a SansAmp Acoustic DI and into the board.