Check out Guadalupe Mtns National Park. You can make the Tejas Trail connect to several other trails in the park, making for a long loop, or an out and back if you wish. It will be like Big Bend in the fact that you will have to carry all of your water, but there will be more vertical loss and gain.
for more info on the park:
http://www.summitpost.org/area/range...onal-Park.html