Sorry to use your topic, but i have the same question, but i already did some research.
Most of the people use poly bags, and they buy from eBay and Amazon.
The problem is i don't know what poly bag to buy and the "correct" size.
Some people say 9x12 other say 10x13 and 12x15 and are these bags that are on eBay are that good? They are "resistant" ?
Thank you =)