Thanks for the replies! Sorry about the lack of initial info, i'll try and add some more.
On the topic of drooling, i was thinking the breeds i mentioned would drool less than say a st bernard. I personally am not bothered by it, but OH is if its through the house haha.
I want a dog as a family pet, I would like to be able to be home alone when OH has to work overnight and feel very safe, as well as feel safe going for walks alone with the dog. I'm working on the theory that no one is going to come after a woman who is alone if she has a big dog at her size. I hope i'm not sounding too paranoid here! I'd just feel safer with a large dog than a kelpie or a begal :p Plus i adore large dogs.
I have grown up with a jack russel and I got a Golden Retriever when i was 14, trained her through puppy school and follow up obedience classes. Absolutely loved the process of socialization and training, and of course owning! She lives with my parents still, no way were they letting her move out with me :p love her too much! I think shes a bit big for her breed, 60cm at withers and around 40kgs.
I understand I will be going from one of the most trainable breeds to prehaps one that is not so trainable, but i'm excited for the challange and know I will have support from a local obedience trainer (part of the Delta Dog Society i think its called?)
My OH has owned mostly rescue dogs whilst growing up, a bull arab, rottie, maremma, irish wolfhound and others they dont know the exact breeding of.
I actually dont have kids, yet :p plans for starting a family are about 4-5years away, but of course the dog I get now will still be around when we have young children, so socialization with children will be a big part of my training plan.
As for time, I'm studying full time by distance, so i can manipulate my time as i please, which is great! I'm also home all day most days.
We live on roughly an acre (fully fenced) with neighbours maybe 200metres away, seperated by horse paddocks. I have thought about how 'something rare' can make it a target for theft. From my understanding of the Tibetan Mastiff, that wouldnt go down too well if someone snunk in to try and steal him! It's definitly a consideration though. I guess i mentioned rareness because thats the kind of categorie the dogs that make it onto my short list are. Not to sound snobby at all, i just like them and find them really interesting to research :)
The dog would be allowed inside at night and when the weather is unfavourable (too hot, stormy ect.)
I've never owned a dog that I didnt raise from a pup, but would consider it if the right dog came along.
I also was thinking the same raineth, that the size alone should mean people wouldnt enter my property when Im not there and such.
I have seriously looked into the Tibetan mastiff and am in contact with a breeder, it could be a long process though so I thought i'd get some more opinions and ideas of potential breeds so we end up with the right dog :)