My fuel system consists of 2 11 gallon tanks, one in each wing.
Fuel lines from each tank run to the rear and join behind the baggage area, then a single fuel line runs down and follows the bottom center stringer forward towards the firewall.
I installed a 2 gallon surge tank just aft of the firewall. This was an aluminum race car tank, but was 4 inches too high to fit so I had to modify it to fit. My aluminum welding skills are not great but a pressure leak test didn't show any leaks ( surprise!).
With the tank mounted, the fuel line was plumbed into a lower port. The “out” line goes to a ball valve and a filter before going through the firewall. The valve and filter are hidden under a narrow center console which is easily removable for filter service.
The console will also be the location of the manual master switch for the electrical system.
The surge tank is vented thru a line that is routed up the right forward structure to the wing root.