Goatless is dead on with his info. Use conventional rubber bushings and you'll enjoy a quiet, smooth riding wagon that won't need any additional attention. I checked Rare Parts and they list all suspension bushings on their site as available. Yes, they're on the expensive side but the parts are available and you won't find better quality anywhere else on the planet.
http://shop.rareparts.com/smtp/shopd...&%20COMPONENTS
I personally prefer a smooth ride, so I use standard Monroe-Matic shocks. They're as close as "stock" in operation that you'll find today and are reasonably priced to boot.
As far as springs go, check your ride height on level ground. I doubt it'll be close to spec since coil springs love to sag pretty quickly, but you may get lucky. There are several outfits that custom build coils springs in both stock and modified heights and spring rates.