MK2 Valver - what grade of oil ??

[Agreeable Slick]

there are two, one with one without. Generally just ask for a Mk2 non return oil filter. the parts guy should know what you mean either that or he is a goobert. 

[rubjonny]

All genuine filters from VAG will have the non-return valve in, they only have one type of filter for the 16v anyway!

If you get one from GSF there are several, just make sure you get the one with (genuine) next to it.  The ones sold by http://www.vwspares.co.uk are MANN filters, which are VAG quality items

[Agreeable Slick]

The VAG dealers still have the two different types AFAIK, each one i have been in has given me the option. I think the ones without valves are being discontinued though. SO might just be back stock they are trying to clear.

[rubjonny]

There is only one type of filter listed on ETKA for the GTI 8v & 16v (and the carbed models too)
I think you might have been offered 2 different makes rather than one with & without the non-return valve.

The PG code engine has 2 listed for it, the one above and another type which looking at it it seems to have been discontinued.

There is another one listed for what I assume are Diesel models? (JP ME 1V JR MF RA SB)

Edit: Though thinking about it, my copy of ETKA is quite new so the other one you got offered may have been discontinued like you say and not be on my copy.  But the way I see it I doubt VAG would sell oil filters that could potentially starve the tappets of oil and make the car sound like a bag of spanners, I'm sure there would be complaints

Thinking about it even more though, the older MK2s didn't have hydralic tappets, so would they even need the top end non-return valve?  That could be why there are 2 types!  Ah isn't speculation a wonderfull thing