Hey guys, best bet is to look on either
http://caraudiosecurity.com/shop/home.html
or
http://caraudiosecurity.com/shop/home.html
both these sites have stores in tottenham court road, london. They are really really cheap because they buy in immense bulk. In most cases you will save double on what you would pay at halfords and at least these guys can give u advice and know what their talking about. Personally i would go for a set of infinity components in the front. You can get a set of references for like £70, kappa are generally a fair bit more and to be honest you dont notice the difference unless your going competition.