when ever i get a pup i only purchase from stock that i have seen worked or from people who have recomended it, i never buy from adverts from papers , the best stock never need to be advertised.
i would go down the reliable road and go for a 3/4 grey 1/4 collie , they poscess plenty of speed and brains, they will do fox aswell if introduced propperly,
but dont be buying a hancock , or you will be just wasting your time and money. all the ones ive seen yapped , but some people are not put off by that.
good luck in your search