[Perfectlap]

+1 on wheel dynamics. They used sell the Carrera replicas for $700. I kick myself for not buying a set to run during winter.

Those 987 turbo replicas would look nice. I think you need that Porsche clip that keeps the e-brake tied back. You should also consider weight if you are looking at other wheels, if your shocks are still original a heavier wheel will make the ride very rough, double the rattles and noise. My factory Carreras are 20 pounds, the stock 17"s were about 30 pounds. I wouldn't go any heavier. And I don't think there's any point in paying more than $1K for wheels since they'll most likely be cast alloys which will bend like a Pepsi can just like $2K fancy brand cast alloys. Forged are bomb proof but then you're loking at $800 per wheel unless there are better deals to be had on a used set.
Although for Boxster fit there aren't many choices as far as forged without going to 19" which will severely limit your tire choices and they'll be $$$$$.