from what I've heard Rival S or Bridgstone RE71R are both good.
as far as the dunlops. based on their previous progression, the z2 *spec will be better than the z2. but i havent heard any feed back yet.
the hankooks have a lot of grip, but need heat. so if you race in a hot climate, they are good, but they suck in the cold/damp. toyos will overheat easily, but have huge grip until they do.