16v sump pan is VW only and made of alloy so it's expensive ! 8v won't fit so don't bother with a steel one !
According to the info I have you can fit the 8v steel ones to a 16v.
Also fairly (99%) certain that my 16v has a steel sump fitted, will check at the weekend.
Any reason why you say the 8v steel one won't fit - I looked into it a while ago when I wanted to fit sump baffles and the info i was given at the time said they were interchangeable as lonh as you used the shorter bolts for the steel one.
I haven't tried this yet, but am interested to find out if you have had problems going down this route. The gasket is the same for the 8v and 16v so the shape is the same, and as I said it looks like my 16v has had a steel sump put on sometime earlier on in its life.
Cheers
Paul