I have some 224s with Michelin Pilot Super Sports all round. From memory I think 5mm-ish on the fronts and 6-7mm on the rear, but I would need to confirm. The rims are in very good condition. Again, I would need to take them out of storage to confirm the exact condition and take pictures, but I'm pretty sure they have no kerbing and only a couple of small marks. Here is the best picture I have of them at the moment, just to give you an idea:
The price I had in mind was £650, based on condition and the tyres, but you would have to give me a couple of weeks check them out properly because I don't want to waste anybody's time - hence no for sale ad yet.
I live in London in a shoebox, so they are in storage in Aylesbury, Bucks. I was going to keep them, in case I ever sold the car, but apparently it isn't cool to keep half a Z4 worth of spares in your parents' garage for several years. :roll: