Which lines?
the lines from the fuel fill to the tank is an A2-15 rated hose available anywhere that caries it
the lines from the fuel tank to the filter head are A1-15 rated hosed available anywhere that caries it.
if you are talking pre-terminated engine side hoses between the fuel pump and fuel logs, then yes, those are Volvo Penta only. However there are hose shops that can make appropriate MPI low permeation rated fuel hoses