I’m so sorry you lost your dog. My heart goes out to you.
The snappiness - honestly, I feel this could happen with any dog of any breed. My working cocker was purchased by his original owner during lockdown and is now fearful of strangers, can be reactive, resource guards, etc. But many lockdown puppies have this problem as adults. And any dog who is not properly socialised could have the same problem. It’s really a case of trying to find a specific dog with a good temperament, and then working with the temperament you get.
Show cockers tend to be lower energy than working cockers, yep. Working cockers tend to be “fizzy”, if that makes sense. Always moving, always wanting to do something. They are notorious for pulling on the lead, though I’m sure training could overcome this. I’m still working on it with my cocker. I’m a dog walker and have taught nearly every single dog I’ve ever walked to walk on a loose lead, yet 6+ months in with my cocker and it’s still a struggle.
It sounds like you have a good amount of time available. 1-2 hours of off leash walking per day should be great. Then a lot of time spent on training and mental stimulation.
Basically, if you want a dog you absolutely have to constantly provide activities for (including teaching and reinforcing doing nothing - because it usually doesn’t come naturally for them), you could consider a working cocker.
If you’d rather have more flexibility and the ability to get away with less some days, go for a show cocker. They still tend to be bouncy and wiggly and energetic, just not on the same level as working cockers.