Bear in mind that I started with a VW sedan wiring harness and then modified the snot out of it to suit what I wanted. You should also add at least three extra 12 ga wires from the dash to the engine compartment, just in case (it's OK to thank me later).
OK, my first suggestion would be to send an email list of everything you need (below) to Carey Hines at Special Edition and get him to quote you on the package. That way, you know it's already being used in Speedsters AND it will all arrive at the same time.
My second suggestion is to get the following from NAPA. These are all Standard Motor Products part numbers (cross-referenceable by NAPA).
Brake switch - Depends on your master cylinder, but a 1970 from Bug City (113945515HG) will usually fit most anything. You don't need the three terminal switch as the third terminal drove the dash "Brake Failure" light, which we don't have. I strongly recommend NOT using an hydraulic, Master Cylinder switch as they all come from China these days and only last a year or two. Instead, get a SLS-40 mechanical switch at NAPA (used on Chevy products from 1937-1962), mount it to the floor so that the brake pedal actuates it. Done forever.
Wipers: You said you have this already, but I like the 91064056 from speedwaymotors.com It's everything plus a bag of chips.
Headlight switch: Standard DS-142
Headlight relay (fused): RY-2
Floor mounted Dimmer Switch: DS-70 or DS-72
Emergency Flasher - There are so many different variations of this circuit that I can only guess. Tell us how you intend to wire your e-flashers (Alan has a cool circuit) and we'll recommend something. A universal, push-pull foglight switch is perfect, but I can't be sure. Mine is a VW E-Flasher switch (1969) with a bazillion terminals on it - don't go there, as it's total German over-design.
If you don't use a floor dimmer switch and want a latching headlight relay toggled by your directional lever, then get a VW 311941583AX (bugcity.com), and use it to drive a power relay (RY-28) to power the headlights - That way, the VW relay will last forever.
Ignition switch: US-129
Door switch (for courtesy lights): DS-206 or DS-251
Universal, 30-amp relay: RY-28 Used for anything under 40 amps that needs a relay - oil cooler fan, starter solenoid (to save the key switch), you name it.
I guess that's it for now..... You doing that email to Carey yet?