First off....new member....first post. Been dreaming of hiking the AT ever since i read A Walk In the Woods as im sure 100% of you have read. Im 18 now and going to college at West Virginia University. Planning on taking a semester off and a summer and Thru Hiking the AT with one of my friends. I have been browsing the forums for a few months now and am DEFINITELY not new to backpacking. Im an Eagle scout and have had a lot of exposure due to backpacking through the Scouts. Done plenty of week long trips etc. But nothing of this magnitude. Now to the actual quesiton....

My friend and i want to hike the trail relatively fast compared to most people. Seeing as we are young and in pretty good shape can handle a good amount of miles per day. We're aiming at around 15 at least, to 20+ per day, and we want to get ours packs light. As i said, im not new to backpacking, but i am new to pretty ultralight packing. I just want to know about how light is it possible to get the pack while still being comfortable? Also, no tarp tents for me...i like my MSR Hubba. I always use a filter or some form of treatment, and no homemade alcohol stoves either. Also, i was looking at an Osprey 50 liter pack to use, good choice? Any info or input would be greatly appreciated!