When you put the specific VAG part number into the website it does come out with a specific spring item number (for several manufacturers). So for mine which is an FL suffix it has a different part number listed to one that has a FK suffix. How true to original that is I do not know, but the spring manufacturers do seem to list based on the OE part number.
If you try searching on some websites by engine type. i.e 170bhp diesel they give you the standard (non sports suspension) springs that they use on other VW and Audi cars so you need to be careful.