Porsche does not sell the fuel hose that connects both fuel rails. If your hose becomes punctured or fails, you will be forced to buy a new fuel rail (at a cost of $600+).
Based upon some research, it looks like Porsche used a Polyamide/nylon type hose with a rubber surround. No manufacture sells a polyamide hose in a 9.5MM (or 3/8") diameter. Wayne Dempsey used regular fuel hose in his 101 projects book with dual fuel hose clamps on each side. I purchased a 25 foot roll (thats all I could buy) of some high quality goodyear/continental hose and used some on my car with some oetiker high pressure crimp style clamps. Consequently, I have enough hose left for 6 kits. One kit contains a 3 foot section of the hose and four oetiker high pressure crimp-style clamps. I am asking $25/each shipped to your location. This is just purely the cost of the hose, clamps and shipping. I can do $17/shipped for just the hose section.
The specs are here:
https://goodyearrubberproducts.com/2012pdfs/Goodyear_Commercial_Truck_Belts_and_Parts/files/assets/downloads/page0032.pdf
It is good up to 100PSI and 275 degrees F. PM me if you are interested.