rub a spot of bees wax on those zippers. It helps a lot, and makes them more water resistant too.
try here they even have a universal sampler that gives a 1"x2" patch of everything. and larger individual samples(each for a fee)
try the vinyl coated polyester it's like the stuff ortleib uses
http://www.owfinc.com/Fabrics/fabricmain.htm
they also have a polyester oxford and a cordura like polyester..lots of cool stuff