I think one of the 'issues' is the fact that you have jumped from a well-behaved, aged, trained to your lifestyle, Boxer to a working cocker puppy. I don't think you could get more different! I recently bought a puppy after some years of owning older, trained, calmer springer and cocker and OMG
You forget how difficult it is owning a puppy regardless of how it is bred. They are evil and sent to test us
Only you know what's best for you and your family but I know loads of working cockers. Some workers and some in family homes. It is true that in family homes, the family needs to be prepared to work harder but they use quite a few training games that I use cos I don't want my 'showgirl' to forget her roots!!
At this point I just want to add that my OH works away and we have a 10 yr old, 8 yr old, 6 yr old and 18mth old as well as 4 month old Saffy(cocker), 3 yr old Cody (working springer), and Ruby 8 yr old(cocker) and I work from home.
We have a treat ball which kibble falls out - a much loved game
We play loads of 'find it' games round the house and garden. You can involve the kids by 'hiding' them but they are easy to find as they are usually giggling!! Our lot love finding the kids.
When out walking, we hide from the dogs. Thye love to find us and it greatly improves recall.
Obedience training - total must in our house and Saffy is mentally knackered after half an hour!
Swimming for the dummy - not strenuous on the joints but works the mind and body well!
Good luck with whatever you decide!!