Zoey makes some very good points. IMO a good personal protection dog needs to be VERY well socialized in order to distinguish between normal and threatening behavior. You can't have them wanting to unjustly attack everyone within sight in public nor would it be beneficial to have them locked in a crate at home while a "visitor" is attacking you. You mentioned both but I don't see that you ever directly stated if you want your dogs to be guardians of person, property or both? I agree that a decoy with experience with Neos and the arger molosser type breeds would be your best bet. Look hard and find one that is familiar with the breed traits and actual personal protection training - it's very easy to find helpers/decoys that are very sport/trial based and that is not the kind of evaluation/reaction you want this person to accomplish with your dog. Keep in mind that just because someone has a sleeve or bite suit doesn't mean they'll be beneficial to what you want out of your dog.