Visit the Long Riders Gear website. They are the bomb for trail / long distance riding. They have all kinds of stuff (including saddle bags for trail riding). I would personally recommend the Stowaway brand. I have 2 kinds & love them both. Stowaway is what all the NATRC / AERC riders use. Hope this helps,
If you look around thier website you can them in all kinds of fun colors and they have a variety of styles as well.
Mine have lasted for several years and I can just throw them in the washing machine and they look like new. I added a couple of ties to mine and set them up so I can flip them around and use the on my english saddle as well, like this: