Here's an article published in Eastmans.
http://www.eastmans.com/ehj/129/reviews/game-bags.html Basically you have four choices; synthetic bags, cotton bags, cheese cloth bags, and home made bags.
The synthetic bags are lightweight and reusable but they are expensive. They are a good deal ONLY if you think you will take the time to save the bags and put them in your washer after use. They dry quickly so you can rinse them in a creek and hang them to dry. I use them when I'm backpack hunting.
http://www.pristineventures.com/products/game-bags.html Most people use good quality cotton game bags and throw them away after use. Most sporting goods stores will carry game bags. Get the large size for elk. You need four big ones and I also use a couple of small ones because I don't like to store the loose meat in the same bag as the quarters. I figure there's less chance of the meat spoiling if it can breathe and storing the loose meat in with the quarters reduces ventilation around the meat.
The cheap cheese cloth bags are worthless for elk. They are generally too small, and they will tear too easily and the weave is so big that they don't do a very good job of keeping insects off of the meat.
If you or your wife can run a sewing machine, you can make your own out of old pillow cases and bed sheets. They are a little heavier and they may not breather as well as the cotton bags.
In September it could be warm enough that you could be concerned with meat spoiling. So you might consider using Game Saver citric acid spray. I ordered it over the Internet from Indian Valley Meat Co., in Indian Valley, AK.
http://www.indianvalleymeats.com/about.htm KC