Doesn't matter where it came from its here now, but yes there were a few sites that helped with the info.
From some reviews the racing beat may not be a bad choice either everyone seems pleased with them, but if you trying to stay "mazda" and can handle the front then shouldn't be a problem, only downs on them (and this is really for any aftermarket spring) is that you'll want to change out your shocks also but I think you were already planning to do that.