Your dad has wonderful tastes in books. I've read all 4 Complete Walkers as they came out, and they helped me make better-informed decisions over the years. Sometimes the amount of detail can be overwhelming, but it's all thorough and well-grounded. You can't get much better.

Just remember it's primarily oriented toward backpacking in the western US, so some of the techniques and gear suggestions (such as four-season tents and how much water to carry) might be overkill for those of us who hike in the eastern US. (Berger's books have a bit more information about hiking in the eastern US, which is why I usually recommend them to beginners. But Fletcher is still my personal favorite.)

The Aether 60 is only 2 liters larger than the Kestrel 58. Give them both a try before you buy; the local outfitter would probably let you bring in your gear to test-pack the pack, and let you carry the loaded pack around the store for awhile.

As far as tents, I prefer the MSR Carbon Reflex 1 (or, for half a pound more and $150 less, the MSR Hubba - identical in design, just not as light.) I've got friends that are equally passionate about their Big Agnes Fly Creek 1 and Copper Spur 1. And as others on these forums will tell you, TarpTents are an outstanding, roomy, lightweight option. (I prefer the CR1/Hubba because I can pitch it without the fly and have an all-mesh shelter on a hot, muggy, buggy August evening in Ohio. You can't do that with most TarpTents.)