hard or rubber line to fmu?

[992GNTme]

okay im a newbie and i have looked an looked and cant seem to find a answer to my delima i am starting on putting my turbo kit that i pieced togeather on my car next week an im not sure what kind of line to use to the fmu for the feed and return a friend has told me to use a hard copper line but someone else told me it would be fine to just use a rubber line so i jus figured id ask an real dsm tuner instead of a honda guy any info. twards that would be really helpfull thanks....