I can't give any advice about the clipping as I have no clue
As for the neighbors dog....I would recommend meeting with your neighbor to address this problem before you add to large dogs to it. It would be awful if one of your pets was injured and you were faced with making a life or death decision on investing hundreds or even thousands of dollars to fix a pet. Does your neighbor have a fenced yard or do they keep him chained out doors? perhaps you both can invest in sharing a fence or electric fencing?