No problems with 08 North monofilm here. Seems the same as 07
As for sails, Ram is best match to Isonic, downhaul is not a problem, you should be using a winch in any case. Also see people doing it by hand with a good extension like Streamline.
You should think about the 9.0 and take the bottom cam off if you dont want 4 cams, but it works fine out of the bag as it is.
S-type is a big improvement over the Daytona, more low end than the Ram, but less stable.
Think you should also consider Redline 9.0, light, short boom, powerful fast and a joy to use