Totaly overkill,
my little brothers mk3 with 300bhp Zetec turbo on 803`s EASILY runs with no need of greys, at all!

underbody tank with standard XR/RS fuel pump top feeding a boot mounted swirl pot, this in turn can graviry feed a 044 (gpA) Bosch pump, these can fuel easily 500bhp on many different applications (not shit ebay jobbie though)

then choose your feed lines to the fuel rail

-8 is normaly choice of use

fuel rail pressure is normally 4 to 5 BAR