Stacking chips refers to AMC7135 regulator chips - see Relic's thread on that. Try 3/4" PVC pipe for an 18650 adaptor. You'll have an issue with length though and will need to make a spacer from a bolt or something being careful it can't short out to the battery tube.
I'd suggest picking up various gauges of wire. You'll need something small for the driver to emitter wiring - like 22 or 24ga (others can chime in as 22 might be too big sometimes). Look for silicone/Teflon coated wiring. Also, I'd recommend 63/37 solder, but 60/40 should work. Make sure it's for electrical work and not plumbing solder. I use rosin core solder.
-Garry