I've switched a lot of my smoking to a dry brine also... two cups brown sugar, one cup white sugar, a cup of plain salt, and a handful of lemon pepper or other spices to taste. After coating the pieces (or whole fillets for a small fish) and sitting overnight, I rinse off and baste the fish with homemade pineapple-habanero sauce before smoking with alder. Great stuff.

For shipping, I'd recommend wrapping the inside packages up with small blue ice packs and newspaper around everything. Then throw the whole package into the deep-freeze for a day or so before shipping it. The problem with vacuum-packed food is that it's susceptible to botulism because it's anaerobic. Better safe than sorry!