Also, it depends on which filler you're using to bulk up the epoxy for the fillets. Colloidal silica and microfibres for example use several times more resin than the low density fillers. Here's a quick reference from West System
http://www.westsystem.com/ss/filler-selection-guide/
Personally I would want to bed the stringers with something in the middle of the chart like micro balloons.
Why would you be using 1708? While I've never worked with the stuff, I would say it's overkill, and it might be a bitch to drape over the stringers. The only way I'd be using that stuff for stringers would be if I were using a foam core for the stringers. Structurally, with the exception of the stringers that go under the motor, the stringers add stiffness to the hull by tying the floor to the hull and creating a box beam, and somewhat less so, the actual stiffness of the stringer. Really, coating the stringers with any glass would be overkill if it wasn't for stringer rot. At least when the wood rots there is still a bit of structure from the glass wrap. I would think a single layer of 8.7oz 12" tape would be plenty if you did a good job and made sure there was no where for the water to get in and rot the wood. It'd be a lot easier to work with, use up a lot less resin, and be cheaper.