Stock style 3/8" OD steel line should be more than enough on the pressure side of the pump. That is what I run on my warm EFI 496 run on bothj track and X country. No issue. The stock style steel line also installs and packages well and safely.

I run a return style system with regulator in the engine compartment and 5/16 stock style fuel line as return. At the tank and engine ends, I use flare connection to pipe thread and AN racing flex hose.

The hard part is the suction side. If you have in tank pump, no issue. Run 3/8" steel line to the engine compartment with appropriate adapters at the ends. If you run an external high pressure pump that is tough. Most high pressure pumps do not like any suction or restriction on the intake side. External did not work well for me. An in tank pump is much better.