Some manufactures are listing one type of spring for the turbo models(16vt+20vt)and another type for the n/a models(16v+20v)which sounds logical to me.
However, other manufactures are listing one type of spring for the 16vt and another type for all other models(16v+20vt).
Im confused now, so can anyone shed some light on this?

the turbos and non turbos are different weights, so its logical to have different springs

IIRC, the Eibach springs for the 16VT are progressive-wound, whereas the 20vts are linear - not sure why.

This is my concern Nigel as the Apex springs im looking at list the same spring for the 1800/2000 16v and 20vt.
So you will have either a correctly sprung 20vt and oversprung n/a or a correctly sprung n/a with an undersprung 20vt......

I'm guessing on a 16v they would be rock solid but on a 20vt they are ok.
I've used the Apex springs on std shocks, it's ok at best.
Get youself some uprated shocks also, it makes the difference.