I get the majority of my parts from American Classic and Jim Carter, both of which have been mentioned above.
I also have used
Chevs of the Forties . They seem to have a fairly decent selection.
If you're looking for pre-bent steel brake lines for a 3/4 ton or larger, go with
Classic Tube . The other vendors (or possibly THIER vendors) do not seem to have the patterns, and I was unable to provide a complete set for them to make them from. (The rear lines had deteriorated very badly.)
Good luck!
