goldens are a great breed for your situation.... very gentle, loving, great with kids. a puppy will help your wife get over her fear. and don't be afraid of puppies. as long as you understand they are puppies (and the sometimes destructive, chewy behaviors that go with that) you'll get them past that stage and have a lot of fun doing it. watching the pup grow up with your kids is priceless.
if you establish that you are alpha right from the start, and make going out on the leash a fun thing, the dog will associate the leash with going out for walks, rides, etc and will be happy as soon as you pick up the leash. it's not hard to train a dog to come, sit, heel. just make it part of the walk with lots of praise. a well trained dog is easy & fun to take out places - so both you and the dog will get the benefits. firm & loving, and above all consistent - just like with children.