Furry home security systems

Strange the way families change over the years, or even, over one year. I'll skip some of the obvious stuff, and get to my point. (I know, you are all disappointed at my lack of commitment to meandering tonight...) Until very recently we'd had a rottweiler in our family for the past 13+ years - the entire time Wife and I have been together, and I actually had a 5-year-old rottie when we met. ("You have what kind of dog?" said then-new-girlfriend, turning pale.) Rottie's are wonderful dogs - kind, gentle, sweet.....the only thing that gives them a bad reputation is people who either abuse them, or train them to be fierce, or both. Sure, they are big and strong, and that is enough to get them into a certain amount of trouble - they can easily knock people over in their enthusiasm to say "hi" or dig up a yard, or furniture, without even trying (puppies should be crated if you aren't home). Even though both of our rotties have been the sweetest dogs ever, having them around has given us an added sense of security. A big, strong dog laying around the house, barking in the yard, and staring out the window tends to make a house less of a target than many others. Wife recently admitted she does not feel as safe now that our dear Jaxon is gone. Jordan, the dalmatian, is a wonderful, sweet boy with a big, strong bark, but he doesn't exactly have "guard dog" written all over him. When it comes to his instinct for alarm system monitoring, and sounding out an alert when odd noises occur....well, he's pretty darn happy to stay asleep on the bed. Perhaps this summer we'll add another addition to our doggie population. We're thinking maybe a boxer this time, or a rottie-mix. I'm just not sure I'm ready for another purebred rottie. I want to honor the memories of the two we've had, and allow a new dog to create her own identity.