I have a Macpac that I got in 1997 and is just as good as the day I got it, and it's seen a fair bit of the world.
However, forget brand names, the most important thing is the FIT of the harness for YOU. A pack that rubs, no matter how expensive, is no good. Test different ones out in the shop with at least 10kgs in them, and by the way, you shouldn't carry more than a third of your body weight as a rule of thumb.
Rather than a swag get a good self inflating mattress - test them out too, especially lying on your side to see how your hip goes on it.