mahle

I've just bought a Mahle cabin filter off ebay (it's the activated carbon type), and it's too big to fit into the frame. It's a Mahle LAK 63 filter, BTW, which references to the vw bora and golf MK IV. If I compare it to my old filter, it's about 5mm too thick. The old one (non-carbon...

Does anyone have any preferences as to what pistons to run, are there any horror stories about any makes any good points and bad points about one another?? I've been looking at a set of 82mm 9:5:1 JE's with the ceramic coating on the crown, or a set of similar Mahle pistons, just after a bit...