I'd probably go for a standard box. You can fit a panel filter in it, but I personally wouldn't bother TBH. Standard paper one is fine.
 
disagree i think aftermarket filters are much better for letting the engine breathas the micro size is much high so let through more air and noise escape
 
Update-

I replaced all boost and breather hoses, got my exhaust blowing repaired and took off shielded cone filter and gave it a good clean.

I notice for the first 15 mins of driving the car sounds perfect but once she is hot I still get this extra growling noise when I floor it! I took her to a VW garage and they came for a spin with me, but they tell me its nothing to worry about.

Maybe im just too fussy but its never made this noise in the past lol
 
Just wanted to let you all know that my problem was manifold to downpipe gasket blowing. thank you everybody for your tips and advice.