any wires will do, even paperclip...Anything, as long able to conduct and with continuity can be used..
the wires you need are preferably multi strand(easy to work with then single strand thats usually harder), not too tiny/thin one(coz even when being soldered, any excessive movement or adjustment, theres tendency for it to break)
if you go sim lim tower as others have mentioned, you will find jumper wires selling in a roll type. Those will do.
Anyway, A/B switch is all mechanical(switches and input/output jack). The only thing electrical is the led wiring to the 3pdt/2pdt switches, battery snap and input jack wired as on/off switch for LED, So theres no tone loss or special components needed to do it