Here are a few from my build:
I bought pre-made steel lines for my rear axle, and used a pre-made block/rubber flex line. The steel parts were painted with the rear axle. The rest of my lines were custom bent from straight SS tube. If your lines don't show, reg. steel is ok, but I like the SS for the exposed lines. If you do use SS, polish the tube FIRST as it is tough to machine polish later. I like using AN fittings (the nickel plated ones) but I have seen some nice steel lines with the steel fittings. SS is next to impossible to do the double flare, so if that is the way you are going, steel is the ticket.
As for running your lines, you can use stiff wire (coathanger) to try the layout before bending the final ones. If you have not bent or flared lines, practice on some old lines first to master the bender and flare tool. If you don't have the tools, I think Autozone and Advance can loan them. Here's a tip I learned the hard way on: Look at whre you are mounting the lines (brake or gas) and make sure that they are accessable later if you have any issue, but are NOT in the way if you need to jack or place jack stands on the frame.
I like a lot of clamps on my lines, and just drill and tap the frame for the screw. I used the SS type, but the adel type works good too.
Make sure you check the length on both of the front flexible lines before ordering. There can be a difference from side to side. Again, I used SS flex lines as they are exposed for the world to see. Make sure to get the good ones from a reputable place. Some of the cheap ones at the swap meet are chinese junk. I don't need to lose my life over a $10 hose.
Not that you need to hear it, but it is always worth repeating for all the new builders, Brakes are NOT the place to be cheap. Do it right or don't do it at all!
