MINI: I'll have to get back to you tomorrow on the exact weights as they're written down at home and I don't remember the exact numbers. But I can tell you the Saturn tire/wheel combo is about 2 lbs. lighter than the OEM tire/wheel. This is with a 205/50/15 Kumho V710 R-comp tire mounted on the Saturn wheel. In other words, not a huge weight reduction, but it's something and it's nice for the price.
As for the specs, the Saturn wheels are 15x6 with a 50 mm offset, so they fully satisfy SCCA stock-class rules. This thread has more details:
Group Buy Wanted: SCCA H Stock legal wheels for Fit