Running with dogs? what breeds are best?

i was thinking not anytime real soon but when i move out. of getting a dog(:: and using him as my running buddy! im a very dedicated runner and i love dogs. but i also know certain breeds have joint problems. my mother has two huge german shepards. one has hip dysplasia and the other wont walk a 1/4 mile without just laying down in the road and sleeping. hes 100lb dog. i cannot just drag him along. so i was wondering what breeds were better built for running. god knows i do not want to be responsible for over running my dog i would feel terrible if it just fell over and died. and no i do not want to sound cold hearted about this in anyway. besides dogs are better company than silly boys! (:: so i was thinking greatdane greyhound collie? i love great danes(:: i like the idea of haveing a 5ft companion running along side of me preotecting me from rapists and such. and how do you run with a dog? i would not risk them running after another dog or in front of a car so leach definately but would it be easier to hook it to my waist? and if i needed to reach down and grab it if need be. i dont think running with it in my arm would be good. might get tangled in it!! so any suggestions? sorry ima a little scatterbrained with my question (::