As I said above, I personally wouldn't go K&N, and Pipercross are as bad. Thid is due to MAF issues I had with my 1.8T many years ago with these filters, so would go green cotton or BMC.
As for noise, you may or may not notice any difference. If you do, it will only be slight. But it would be more noticeable once you have your exhaust on there.
I have also previously swore I wouldn't have another Miltek due to problems I had with both my mk4 Golfs and these exhausts. Although the re-sale value of them always seem to bring me back if I'm honest. I think I would be more inclined to go for a custom exhaust though. Stainless Creations down around the Falkirk area make beautiful custom exhausts.