The Continental ExtremeContact Sports are good tires. Great in the wet and can actually hold up to a few laps per session with some "light track duty" (aka not my Z, but my WRX with me learning how the car handles)
I have one beef with them, they will flat spot if you don't store the car properly. You'll need to over-inflate them if your Z hibernates for any sort of time. Here are some pictures of the exact sizes, but with a 9.5 inch front and 11 inch rear wheel:
I currently run the Michelin Pilot Sport 4S now. Yes, they are expensive AF, but the car now feels like a f-ing luxury car. It handles speedbumps, bad roads, and sudden surface changes better than my WRX now (and im on coilovers). The sidewalls on the Michelins are going to be beefier and their wheel protection is slightly better, than the continental, but that's not to say the Conti's don't have wheel guards. you'll want to go with 305/30R19 to keep that speedo reading close to accurate. If you want to go with a thicker sidewall, the 285/35R19 tends to look meatier. I'll post some more pictures with the Michelins in a bit. all the ones i have are heavily edited.
