Here's the formula for a perfect sports oriented 911 w/ a 3.2L or less engine & stockish transmission, w/ SC/Carrera flares, while avoiding specialty tires
Front: 8" ET25 to 30 w/ 225/50 x15 tires
Rear: 9.5" ET19 245/45 x15 tires
alternative for more sporting use
same wheels but 225/45 & 245/40 x15
w/ 3.4 or better
same wheels but in 17"
225/45 & 255/40 x17 tires
for those looking for the Fuchs look
8ET25-30 & 9 x17ET12-15 215 /45 & 225/45 or 225/4 & 245/40
You will need to adjust ride height and alignment to suit the tire and suspension package, these are 8 & 9.5 x17 225/45 & 255/40 x17, w/ 205/50 on 7ET23.3 Fuchs & 225/50 8ET10.6 Fuchs in 15 it looked the same but a tad lower
These wheels are generally not available in Fuchs or Fuchs look, fenders here are 24 5/8" & 23 7/8"