Hi there,
I did have a screamer 116 (05) and I know that the guy that bought me the board has already sailed with 8.0 sail. So I guess, since there aren't that many differences between the 05 and 06 model I reckon you should be ok with sails up to 8.0 m.
Depending on the year of the camed sail, they can be quite heavy. But again, the screamer is a wide board that floats well and so able to get heavy camed sails.