welcome !!! Looks like a definite plan and a really cool project. But just because you're big doesn't mean you have to go overboard. You will be happier with a lighter leather weight, and your pack will last just as long, look better, and the straps will be 100 times more comfortable.. If you look at old world packs, they used about 5 oz. This is my baby (Swiss salt-and-pepper rucksack). If you need any pics of the construction methods, let me know; these are some of the best packs made IMO..