Looking for a backpack

I’m going to do a little hiking in the next year, so I’m looking at backpacks.

I currently have a huge Lowe pack from about 1989 that has too much room, and a small Kelty pack that never really impressed me. I’m looking at the Marmot T2500. After looking at online info I also want to track down a Gregory G Pack and an Osprey Atmos 50. They might be a little big, though. I want the smallest pack that will fit, and I’m 6’3″ with a long back.

I’ll have to go back to the local shop and see if they have an Atmos in stock.