Air filter help?

[MasterMelon]

I have 1.2 clio and want to get an new air filter to make the car sound a little better?

Where is reasonably cheap and how easy are they to fit?

 

[Clioste]

eBay there only like £10 easy as chips to fit but they are crap but might give bit of sound induction kit I mean or just stick an upgraded back box on 3" poss