Knothead--I increasingly lean toward the minimalist side as I age--don't like the heavy backpacks. On the fishing side, a pack rod outfit and a basic selection of flies, along with tippet material and a couple of spare leaders are all you need.
Equipment wise the "musts," to me, are: tent, sleeping bag, inflatable pad, ground cloth, cooking stove, lightweight cooking kit, first-aid kit, food, water filter, change of clothing, and personal stuff. You can, with some planning, get all of this into a bacpack and come in right around 40 pounds. Nice extras are a saw or hatchet, lantern, and perhaps a lightweight seat. For many years I've worked off a list, and I recommend that approach to anyone who backpacks much. You can revise, add, delete, or otherwise change as you see fit.
As for October fishing, I rate the month second only to May in the Smokies.