These are very different breeds with different drives and traits. And, pomchis are not a breed, they are a cross so you would struggle to find one from a responsible breeder. You also need to be careful with the breeding lines of cavaliers, a very high proportion have terrible health from inherited conditions, leading to pain, stressful and expensive vet visits and early death.
To avoid that sort of thing, regardless of which breed you choose, you need to find a breeder who tests their parent dogs to make sure they are not passing on health problems (which vary from breed to breed). That's proper tests, not just a quick once over by a vet to say the dogs are capable of siring/carrying a litter.
Then, you need to think about a lot more than prey drive. What are your views on grooming, trainability, recall, noise, handler focus, friendliness, independence etc?
Finally, I suggest this to a lot of people in your situation.
For the next month, act like you have an adult dog. Get up an hour earlier than normal, take an hour long walk. Do the same in the evening after work - and come straight home from work; no shopping, gym, socialising. Do this every day, without fail, regardless of the weather.
Be aware of the season, and remind yourself every morning that for several months of the year you will be doing this in the cold and dark.
Also put away what you think a dog will cost for food, insurance, vet bill excesses, toys etc, then add 10% because we always underestimate these things.
That will give you a good insight into some of the commitment you will need to make.
Don't think about what a dog will bring to your family, think about what your family can offer to a dog.