Catskill model internal frame packs and were really pleased with them. These packs are very inexpensive yet comfortable and serviceable. It is not necessary to spend a fortune to get a good backpack. Many prefer external frame packs. You should experiment and decide for yourself.
All packs are hard to protect from rain.
Even with a pack cover, rain runs down the straps and eventually gets into your pack. You will find water standing inside the bottom of the sleeping bag compartment. You must carefully pack your bags into plastic trashbags or waterproof stuffsacks before putting them in your pack. It's a good idea to put a plastic bag inside your stuffsack and an additional one around the outside of it. Our down bags never got wet using this method.