The resistance band I have covered in previous posts about home training equipment should last a long time when cared for properly. However, some bands are built with an outer layer of protection that also protects against bands snapping. These can get a little bulky in a bag, but for outdoor use they can take a beating.
For a full kit with an anchor and handles:
For individual bands with handles attached to each band FitCord is awesome but a little more expensive:
If you have bands with built-in handles, but want to "stack" the bands to increase resistance you can buy extra handles.
The handles already come with caribeaners, not all of them do.