Honestly, I wouldn't get either for use in MN. Besides the fact that both lines will get quite coily in water below 70 degrees, there's also the floatability factor.
Because saltwater is more dense than fresh water (due to the addition of Na and other heavy stuff), a more dense line will float in it. Saltwater lines are generally a bit more dense than freshwater lines because they will still float in the denser water, and the added density will aid casting in the wind.
If you want a line that will load up a Predator quick but still be reasonably pliable in MN conditions, I'd look at Rio and SA's bass lines. They're both made for warmer weather, but are still a freshwater line. If you're dead-set on a SW line, SA's Saltwater is made more for east coast conditions and wont turn into a slinky in the cold.
That SA Magnum Sharkskin is also a heavy line. It doesn't feel as heavy as these guys weighed it, but its definitely a half weight heavy- http://www.flyfishohio.com/Scientifi...n%20Magnum.htm