I’ve got 19″ x 245 on a 59 XF, replaced them in feb for £205 per corner. Like audi they eat pirellis, but the dunlop sports have lasted 20k for me, plus have a buffer line to help prevent curbing.
Only hassle I had was sourcing winter tyres, and they ended up at £280 per corner! It was only marginally more expensive to fit a set of cheap 18″ rims with winters by comparison.
I’ve always purchsed through mytyres.co.uk who deliver free of charge to the local garage (hawthornes in Sheffield) who fit them for £10 per corner.
Also check with your insurers, if the 19’s are considered non standard … it will cost, tesco quoted an additional £ 590 to have the 18″ rims on even though they are a factory option for lower models, and £215 for having winter tyres fitted (hence direct line now have my policy).