Loads of the US guys have lowered their cars so I can't see why it can't be done here - no idea on price but like Jonmad says its a £150/£200 option and you wont get it for that price after!!! Just buy an M sport - if you don't, you will always say why didn't I etc. When I bought mine the M sport wasn't an option but I'd definately get one next time.
EDIT Try here :-
http://www.europerformance.co.uk/pag...sub_category=1