The Boer goats and Dorper sheep have spread throughout the southern states since they were imported, with the increasing droughts it might be time to look at African low maintenance cattle as well, along with Holistic management you should be able to cope with the longer drought periods, we had worse in my part of Matabeleland (in Rhodesia/Zimbabwe) but maintained a good level of grazing and browsing, and produced a much higher production/acre at a lower cost than our neighbours in Botswana and South Africa.
http://sangacattle.webs.com/
Some typical pictures, and a few discussions worth looking at on the site.