Vernon Barker 531 tandem - rescue from the woods

Rider pairs will weigh 125-150kg and luggage will be minimal so I don't need to build a tank. I can hopefully therefore find parts on here.

Parts I'm now shopping for, used:

• Wheelset. 36h with Shimano freehub. Anything true will do.
  
• V-brakes or canti brakes. Anything stiff enough to stop a 125-150kg rider pair.
  
• Chainrings. A pair of 36-40t 1/8" rings for the synch drive.
  
• Racks. One front, one rear, cheap and cheerful is fine.
  
• Handlebar. Something for more upright riding, perhaps with a sweep back?
  
  

Parts I can buy new, but in case anyone needs to shift used:

• Chains. 2x track/SS chains for the synch drive.
  
  

Parts I'll probably have to buy new:

• Cables. Fucking long ones, compression-less housing for the brakes.