Don't know about the offset!
I know k-tec do some lightweight 16" rims. Unsure of their weight. I'd like a set of 15's too. Probably get the 15" x 7" speedline corse as used on the clio cup racers. This way i could also hopefully source some old cheap slicks from the racers that have been used but that I could hopefully get a couple of trackdays out of them. Well thats my plan for when my dealer decides to deliver my trophy.
some people run the rims from the lower spec clios. They run 15" alloys and i expect youll pick up a set for not much cash. Jon_r and yozza of cliosport run em on cups but not sure how they would work on the trophy....