From what you have said i too think a A/B switch would be your best bet! The only issue i can think of is having the two heads going to teh amp. I've never realy used the head - cab mix so I don't know about inputs to cabs. I suggest having a look at a cab that is compatible with the heads that you like!
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Guitars: Gibson Les Paul Classic - Gibson SG Standard
Stomp Boxes - Digitech Hotrod & Digital Delay - Boss Compress/Sustain - Morley Power Wah *NEW* MXR Phaser 90 EVH Edition
Amp: Vox AC30
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