The only kit that will fit behind a Pescara with no spacers is the 330mm AP racing kit using the CP5200 Caliper
They're only 7.5" wide there's only so much you can do. If somebody is he'll bent on sticking with the pesky pescaras then get the 360mm B5 RS4 kit its twin piston and an excellent pedal track proven and loads of pads available from DS2500 right through to RS29
They're cheap to buy but discs are expensive but last a long time, even with new discs and refurbed it would be inside of £800 and very OEM++
Top Cat was the first to fit them and gave very good feedback did a ring trip and a track day or two had a few issues with compound compatibility but they always reportedly felt very strong