OP I have 2 cockapoos (gasp!) They are easy to train, came with health tested certificates, and have been no problem whatsoever. Yes, they need regular grooming. I groom them myself. All you need is a set of brushes, which you would need for most dogs, and a clippers.
I can't believe the venom spouted on MN about cross breeds. Yes, we all know puppy farmers exist. We all know puppy farmers farm all breeds - not just cross breeds.
I wonder where your puppy would end up if you didn't take it? If nobody took it I would think it would end up in a rescue shelter. The very place people are urging you to get a dog from. Personally, I would take the pup. If you rescue from a shelter the dog is unlikely to have health certificates and will, usually, have a load of behavioural problems. Not great when you have children.
If you Google cavalier king Charles images, the first 3 puppy images are bright red.
I know lots of people with various cross breeds. None have the health problems MN suggest. Instead of asking a load of internet strangers why not speak to a vet or people who own cross breeds so have experience of them? I belong to a cockapoo club, where we meet up on a regular basis. Considering these crosses are supposed to have so many health issues they are a picture of health and energy. The eldest if the group is 15 years old. Never had a health problem, other than those that most dogs get.
If you have considered getting a dog for a while and are happy with the cav/bichon cross is say go for it!