I've fostered 2 dogs over the last 2 years and looked after friend's and brother's dogs. I enjoyed it very much but, honestly, I'm not sure I would want a dog full-time. I'm obviously not a "natural" dog-owner otherwise I would have taken the plunge as I love dogs very much.
For me, it was the "I can't go to the shops for a few hours, pick up kids from school, take them straight to swimming/other places and come home 6/7 hours later, because the dog couldn't be left that long. Ditto for days out in London, theme parks, cinema plus a meal after. It's that kind of thing that puts me off. It's not something you have to think about every day but it does mean you can't be as spontaneous as you might like to be. Obviously, you can do different activities which include your dog, but I found it was something that bugged me a little bit. BUT if my family were more into the idea of having a dog, it's probably something I would have done by now! And, however much kids are mad about dogs, you will end up with the vet visits, poo picking, feeding, and walking!
I only had to consider it for a few months each time, but you would have 10+ years. Having said that, if you have younger children, look at smaller rescues. They're often more flexible, have dogs in foster as no money for big kennels. Then dogs can be assessed in family environments, meet children, other dogs/cats etc.
For example, Heathlands Animal Sanctuary, Balkan Underdogs, Silver Fox Dog Rescue, Black Retriever X. They all have FB groups. When you do go looking, always join FB groups as often a lot more up-to-date than websites. More "popular" dogs don't even get to the website as they're snapped up beforehand.