The first thing I would do is join the breed club. They have newsletters which they send out which will give you lots of information about the breed. They will also give you dates/places of shows, go to them and talk to lots of breeders. Every breed has its own little quirks and differences. I would do this now, long before you consider getting a dog.
I joined my breed's club 5 years before I actually got a dog of that breed. In my particular breed there is no way you can keep two males together they would fight to the death (and I would not even attempt to seperate two males of this breed). My dog weighs in at 66Kg (and that is pure muscle).
I don't think your wife would have a problem (as long as she wants the dog!), I have had my boy for 11 years now, I handle him more than my partner (I am not a big or particularly strong woman), in fact when I used to take him to training classes I used to hand him over to some of the men who told me they could handle him better than me (a mere woman) he used to go on to make a total fool out of them! My dog is an entire male dog and he has never 'physically' challenged me, but then I have never put him in a situation where that is likely to happen. I don't believe in all this dominance and pack leader stuff anyhow. Dominance does not cross species. I am not boss of my dog, he is not boss of me, we live together in the same house, he obeys some of my rules and I probably obey some of his!
One thing I would say is don't get a dog like this unless the whole family are happy about it, they are not a dog you can 'put up' with or ignore. I would also consider getting a puppy first, then you can grow with the dog and you have the advice and follow up of the breeder. You can also train a pup to your own standards.
Dogs like this are a big commitment. For a start not all boarding kennels will take them, vets bills are more expensive etc. Learn as much about