Hi Andrew
My IS300h Premier (see in For Sale section!!!) has 18" wheels but they are different width front and rear the front tyres are
225/40/18 and the rear are 255/35/18. My premier has all the extras and a comfortable ride, and optionally the Relax warranty through to October 2027, also being 2016 year has only a small increase in VED from £10 to £20 pa from next April, where as post April 2017 300h models will be £180 pa unless a new Government changes the rules.
Good luck in your search.