For affordable reliable vests look at these ones here. I only put in one modular one since the extra pouches you'll need will ramp the price up to the sky.
http://ascmart.ca/product_info.php?c...products_id=63
http://ascmart.ca/product_info.php?c...products_id=63
http://www.oneshottactical.com/Merch...ry_Code=BlueFG
And to answer the question about nylon it'll really depend on the material and how it's sewn, with the dead link none of us can add info on the one you've found.