Found these but there expensive, probably due to the fact there discontinued.
https://www.tyreleader.co.uk/car-tyres/michelin/pilot-super-sport/245-45-zr18-100y-428433
The new MPS4 is probably the way to go.
Welcome along,sorry to hear about this. 30 k why on earth hasn't it got a full tank , really !
I'd be checking that the transport blocks have been taken out of the springs as that seems to be a common failure.