Look for a Sturmey Archer SX-RB3 (band brake model) or the SX-RK3 (disc brake model)
I bought the SX-RB3 for my 'in progress' OCC-based build. I found an online shop in Oregon that had it for around $140. Chopperus gets them with the disc brake setup on them, they're sold out at the moment. But email Alan, he'll let you know when they come back in stock. It's truly the easiest way to get gears in the rear. hahahahahaaa that sounds funny. :mrgreen:
Good luck!
Cheers,
Dr. T