And if you're going to invest the time in attending autocross events and can afford "extreme performance summer" aka 200tw autocross-able street tires, do it. You'll have more fun and have a chance at being competitive, and they really are a huge leap up from all seasons. BUT, the tradeoff is 200tw tires wear out fast if driven on the street a lot, shouldn't be used in cold weather, and aren't the best in heavy rain/water conditions especially when they're worn down a bit. So having a daily set of all seasons and a separate autox set is really the way to go if you can swing it.
If you just want 1 set of wheels/tires, you might go with a lesser tire like the Continental ExtremeContact Sport - still a summer tire and better than OEM all seasons, capable on track, but 340 treadwear so it'll last a lot longer than 200tw RE71Rs and the like.
Used sets of lightweight 17x7.5 wheels do pop up on forums and FB groups from time to time, as do used autocross tires in 245/40-17.