I need your opinion

Ok, so I want sheep. Among other things on my list of I wants are at least 5-7 sheep. I don't care if they are wethers or ewes. A ram might be in the future but I really want my own source of yarns and fibers. Right now is a pretty uncertain time in North Carolina. With freezing temps so early thin year and sometimes our summers hit 100 degrees and someyears we hardly get into the 90's. I have been trying to decide what breed of sheep would be best suited to our climate. Think zone 7 in the for gardening. So far I have a list of breeds I have looked into. Before I list my top picks I want to tell you my deciding factors. I like the look of the open faced breeds. Polled or naturally without horns. I also do not want hair sheep (they just aren't my thing). Lastly I want a breed that can be maintained on grass with little feed, lamb well and raise the lambs on grass as well. So with all that in mind I do realise that I can't have everything so my top choices are Rambouilett, Corridale and Chevoit. If anyone knows any reason not to choose these breeds of has a breed I have not considered please tell me! Every little suggestion helps. I will continue to read and consider all comments for at least the next 6 months before the decision is final.