On 10 acres, a couple horses and goats will keep it "mowed" pretty good. If you get sheep they will eat it down pretty good.  So, with those animals you will only have to mow around the house. I suggest fence in your home site so you don't have horses, sheep, and goats jumping on things that you want to keep.

About the breeds - Central Asian Shepherd, Kangal, Anatolian, a "good" German Shepherd or one of the bully types mentioned by others would do the trick in that weather. Please note that we have Caucasian Ovcharka in South Texas (today's high 106F).. :) with water, shade, and a fan they do ok.