306 GLX induction kit wanted

Hello just got a 306 1.8 16v and just wanted to know what's the best way to improve the induction system? Halfords want £100 for a K&N and £75 for a pipercross kit are these any good or should I do some DIY job that's better?

Thanks, David

Will get some pictures of the car, it's the nice Dark metallic blue

p.s is it true that the car is only group 6 to insure? makes no sense as my Toyota corolla is only a 1.3 and is a group 9!