Where can I get Stainless Steel brake lines?

Welcome To TD!!!

What are you looking for in SS?
Are you looking to replace on the brake system?
All of the steel tubing or just the rubber hoses?
FWD Performance has the SS lines to replace the hoses.
Eastwood has SS brake line tubing and fittings.

As far as SS fuel line...
Summit racing has Braided SS fuel line kits that require AN fittings.

when you cut ss lines , do not use one of those tubeing cutters that have the sharp wheel and cuts by clamping , rolling around the tubeing

this will work harden the ss tubeing and cause cracking when you try to flare the lines

cut it instead with a hacksaw and blow the metal cuttings out of the tube with compressed air