Iv got. Walbro - woundnt bother tbh.
Seat leon fr is direct fit/s3 something needs blocking off.
Changing mine to a s3 one soon.
Mines running 3 bar fpr
On the s3 the second pick up needs blocking off because they have two pick ups as a result of their different fuel tank.
Also the fuel pump you want is an lcr fuel pump.
In addition, an inline pump doesn't pull air through - no more than your standard pump would because your standard pump will serve as a feed for the inline pump.
You can also modify the swirl pot relatively easily, there's a guide that goes into more detail on here. It works pretty well I might add.