Currently I have a Kelty that is about 12 years old. But if I were to buy a pack today it would be either an Osprey or a Gregory. Both are great quality packs and are reasonably priced. My current pack has 2 external pull length pockets on both sides and a smaller pouch in the front, yet they seem to be a thing of the past. More and more companies are going for a more "streamlined" pack. So it is getting harder to find packs with built in ext. pockets. But I`d definitely go for an Osprey or Gregory Pack.
Backpacker.com did a gear review, which included backpacks, not too long ago so you may want to check out their site to see the testers reviews. I would go to a major retailer such as EMS, REI or Campmor and try on the packs and maybe even ask them what they use. But, I would buy it on Backcountry.com because they have a no questions asked 100% return policy, so if you bust it or just dont like it you can return it for an exchange for a refund. It`s kind of cool because if you go to the bottom of their page and click return policy, its only 1 sentence. (I am just a loyal customer and do not work for or hae any affil. with them)
Any other questions feel free to ask!