Michael
I think the 100 Cubera might be stretching it, it seems happy around 60 - 80 grams tops. Try the Heru Tuna 80, it is a bit lighter for casting and has a smaller cup for a better retreive on that rod, this would still be about the max for the rod though.
Ideal would probably be something more like the Halco 135 Roosta! I'm sure Dave Noble could shed some further light on casting weights for you, I think this is one of his light weight fav's.