For the through the car fuel lines we have used teflon lined steel braided hose. This hose uses the same type of fitting as Aeroquip style brake hose. Being -6 hose, it is much easier to fit the fittings than the corresponding items on -3 hose.
It is also smaller outside diameter than conventional hose and means we have been able follow the panels contours more easily.
This is particularly useful as we will be having 3 pipes running through the car, 2 feeds & a Common return.
That's the easy bit, now it's a matter of sorting the plumbing to the 2 electric high pressure pumps