For hubs & spindles go to

http://users.isaac.net/lincoln/

QDS Components - I have requested their catalog as I have been contemplating building a farm wagon. I could not find a vendor for the type of spindles I needed for the (steerable) front axle. Have not received the catalog but expect they will have them.

They also are vendor for the Henschen Torsion Axles discussed in the "2 or 3 Axle" thread under Off Topic & Just for Fun.