To begin I'm going into the Marines I'm currently a Poole. I got to meet a Marine that just came back from a SOI and he said it would be smart to start running with a pack with weight. He said to start with 30 pounds of sand plus essentials, and to later work up to 50 pounds plus water and junk. So I'm wondering what I need weather it be a backpack or rucksack. I preferably would like to stay in the $50 range but will go up to $100. Like I said it needs to be able to hold a lot of weight and I would also like to use it to go hiking/camping so I would also like it to have space. I would like for a built in hydration pack to but if not its fine. And to end I was wondering if any of these would be good http://www.grunt.com/digital-woodland-rucksack, or http://www.grunt.com/bags/digital-woodland-tacpac if not could you direct me to a good site. Thank you head to anybody that answers.