David, Thanks for the reply to my query.
My plan is to use the heavy, stiff "Seal a Meal" bags to vacuum package our supplies for mailing- especially the one that will be packed for 3+ weeks. I'll then transfer into lighter bags for the one week hike segment.
I don't see the benefit of heat sealing but not vacuuming. A knot in a produce bag works fine.
We will have some Ziplocs for things like trail mix.
