Mountain weather is ever changing, keep your options wide open. Include a extra warm layer, the down jacket would be great item. Packs light and small, yet provides good insulating value. lori just posted a trail report where one of the guys in her party didn't bring long pants. The weather got cold and windy and he suffered.
Where and when you hike are the main deciding factors of course, so, to each there own on what keeps you warm.
A good breathable rain coat or poncho with pants are a good layer as well for keeping dry and warm. Lots of options as far as brands. But when I'm active I sweat alot and I don't know if there is a all in one fabric that doesn't hold the vapor I produce.
So far a poncho has been the best for me, since it allows more airflow.
As far as durability of your 1.1 BB, from what I've read here they do fine. Treated with respect as any piece of gear, i.e. no sparks or sharp objects or dragging on the ground it should hold up nicely. I don't own one, but I've heard nothing but good things here. Someday I'll call brandon.
The weight of your whoopie depends on overall length that you make it and what kind of rope you use, so thats a variable that can't be answered. Most rope suppliers online give weight per foot or yard of thier rope. amsteel blue seems popular here for whoopieshttp://www.samsonrope.com/index.cfm?rope=192
This chart displays what your looking for.
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