What dog is right for me?

ok so ill start off by telling you about me and where i live. so the smallest kid in my house is 8, and she doesn't like dogs to much so she has birds and she would mostly not be playing with the dog. ok then i live in just a normal house with a fenced yard but when he wanted to run there is mountains all over and big fields all around my house. ( he wouldn't be alone out there i would be there too) and i have an insulated dog house, but he would come in the house a lot. and that's kinda it. now i'll tell you what i want in a dog. ok, one that is between staffordshire terrier and german shepherd size, one that sheds very little if i brush him like three times a week, one that could defend himself from coyotes if that ever happened ( not kill them just hold them off itself until i got my gun), one that would love me and my family but kinda be wary of strangers, and last a dog that's not gonna be super hard to find and cost over 400$ cause ill probably just look at the shelter for a puppy that is the breed you suggest. ok thanks to anyone who answers and i know its long, sorry, it had to be!