Another option for surge tank - this is what I run with my FI tech - same as your sketch - low pressure pump keeps surge full of fuel with a return back to main tank.
High pressure loop to and from efi and tank. I can get a picture later.
RobbMc Performance Products - PowerSurge
High pressure loop to and from efi and tank. I can get a picture later.
RobbMc Performance Products - PowerSurge