Any of the top-end brands would serve you well for a long time, but I'd be more concerned with making sure a particular style of pack fit me best, and then pick one of the top brands that makes a pack of that style.
For example, I used a Kifaru LH Guide for quite a while, and it never really worked very well for me. It has the wing-style hip belt, and I didn't realize that style wasn't ideal for my body type until I tried on a SO Paradox, with its full wrap hip belt. As soon as I put that thing on it immediately fit like a glove. Packs that fit well help you bear a load with less strain, and the load feels lighter. Heavy loads always suck, but they suck less with a pack that fits your body properly.
