Jeremy, why don't you take a look at the Minima vest kit offered by Thru Hiker at http://thru-hiker.com/kits/
You can get a kit sized for you with Momentum 0.9 oz/yd fabric and all of the cutting, figuring and fitting done for you for about $52. And, you get to keep the patterns to modify for future projects. At least take a look. If you try to MYOG you can easily spend more than this on your mistakes.