http://www.humphrisoxford.co.uk/rally/ Humphris Oxford does various parts, mainly performance rather than astetic though.
Other than that best was is to source second hand parts seeing as the K11 is now 23 years old!
I had my Super S done back in the day, about £80 I think.
My "moddedmicra" K11 Super S Blog!
Dunno where you live but I can recommend Stuart in Trowbridge, Wiltshire he's done all my cars:
http://www.protintuk.co.uk/contact/