Im running a Nismo feed (aftermarket intake pump) into a 5 litre surge tank with twin 044's feeding the engine. Dash 6's all round, however it would be nice to have a dash 8 for the return lines. So, from the FPR it goes back to the surge tank then a overflow line back to the main tank.
You dont need braided lines... Rubber hose is fine.
You can't hear the overflow dropping back into the main tank.
Are your tracking the car? If not I wouldn't bother with surge tanks with feed and lift pumps. A single Nismo will do the job without any problems.