for those who say they ran steel fuel return lines for their SFMU, where did you get the line, what are the spec's on it?

I read posts that said it only costs around $25...but didnt notice where to get it or any specific details on running a steel line.

im trying to decide which way to go; either with the fuel line for fuel injected cars or steel line

easy on me, new to the turbo section

I will likely be posting more questions the closer I get to installing the turbo kit and getting it to run right. Thanks!