They are MASItaly Callistos. I believe that they have been discontinued, but I could easily be incorrect on that one.
I got them from Discount Tire Direct for (ahem) $60 apiece. No, that is not a typo. They were on clearance on the website, and they had 14 left when I bought my set. I was originally waiting for a set of b14 SE-R wheels to come up for sale, but these caught my eye while I was surfing for tires and I couldn't argue with that price.
I have no idea on the weight. I bought them before finding out that weight matters. I will say however that the car didn't feel much different when I went from the stockers to the 15s. It definitely handles better (better tires I guess, wider too - these are 15x7s) but did not really feel slower in a straight line. Be advised this is all SOTP.
The tires are Kelly Charger HR Directional and were also on special when I bought them (hey, I'm an out-of-work teacher, I'm kind of on a budget), in case anyone cares. The next set will be Toyo/Nitto/Kumho, although I have been very happy with the Kellys.