the konis are not the same , if you get them side by side with oe , you will see the spring plate is lower down the shock , which causes the problem with anything bigger than 16 inch weels
how much does the tyre rub , on the spring plate , i found with half worn tyres it was ok , but new tyres the wheel would not move at all
is it possible to get a slighty smaller tyre on the 18inch rim ?
with the 215/45/17 there is plenty of room.
hope you find a cost effictive solution anyhow.
no worries andy , good chatting to you