Firstly, thanks everyone for your replies, its been very useful to read so many thoughtful and detailed answers. Secondly, sorry to have instigated an argument!
I printed out the responses last night and we read it in the pub, where I took in the information while the wife devoted more of her time to oohing and aahing over the various doggy photos - Joelf, your lab + cocker photo especially should come with some kind of government warning, she nearly choked on her drink
.
When I mentioned about not being too vocal, sorry I should have been a little more specific - it wasn't general vocalisation we were concerned about, more the guard dog barking constantly mentality we were trying to avoid out of consideration to the neighbours.
Nicola, we would definitely consider a rescue dog. Basically we were after whatever dog would be happiest in our environment, whether that meant training from a pup (to get accustomed to the cat for example) or a rescue dog.
I think we underestimated how much time and effort was involved, however. It sounds more like even working from home isn't exactly enough - my work is fairly concentration-intensive, so I probably wouldn't be able to give the dog as much attention as would be needed. I'm thinking it would be best to delay (yet again) until one of us gives up work permanently for childcare reasons (at some point in the not too distant future), and then look at a rescue dog that was fine around a young child.
Thanks again for all your replies - its been a big help.
Michael