Ask yourself the following questions here:

At what flow rate (l/min) will my fuel be pumped?

Depending on your flow rate, the size of your filter is determined. The larger the flow per minute, the larger the contact area of your filter should be, the larger your filter should be.

How many gallons do you consume per month / per year?

The total amount of fuel per year is also a determining factor of how big your filter should be.