[skidlids]

Sorry to say the 600 tank isn't suitable for the 620 neither is the fuel filter you have linked two.
The 620 tank has an electric fuel pump inside it delivering 3-Bar of pressure, as such it uses a fuel filter (also inside the tank) that is capable of handling such pressures. The 620 Tank also has a return pipe back from the fuel regulator that is attached to the throttle bodies.

A plastic tank as fitted to mant of the monsters from around 2004 onwards would be one solution but they use a different fuel pump which you would also need to get and as this fuel pump assembly also contains the fuel pressure regulator you really should remove the one that is on the throttle bodies