would go along with the above, but remember the stop / sit up whistle means sit / stop now , not in 2 seconds time, if it dont, scruff it and put it back to the EXACT spot it was when you gave the command, little inperfections like it stopping ten feet from where its told too will soon turn into a dog that just says feck you to the stop command ...
and feck the idea of a shock collar, a sure sign of a trainer with lack of knowledge or experience of dog training, yes they sometimes have there place, but only as a last resort, and not for a basic command like stop.... the ammount of people