I have the sensations brand and my female is big like your male, and reactive. The clips on that harness aren't very strong, I always feared the clips would break. It also chafed under her front legs. I resorted to using a prong with a back up flat collar. I ran a tab on the prong and only used it when necessary so she would get use to walking on a flat.
Because of her reactivity, I tried not to use the prong for corrections because that ramped her up more. I bought the sensation, hoping it would help, but training is what works, not the equipment used.
There are video's of "loose leash walking" training, I'd train your dog not to pull.