I don't know whether I would suggest a specific breed but I would call out a few 'watch outs' on your requirements:
Hypoallergenic
No dog is hypoallergenic. People can be allergic to fur or dander and it's more often dander which is shed skin cells. All dogs shed skin cells but some fur types shed less and/or the cells get caught more easily in the fur so are released into the air less. It is important you know which you are allergic to. Moreover, some people can be allergic to one type of dog dander but not another so it's worth spending time with a breed first to check it won't trigger the allergy.
Finally on allergies, if you cross a cocker with a poddle (for e.g.) there is no guarantee you will get the dander/coat of a poodle. You have equal chances of getting the cocker type instead. You would need several generations of cross parents before you got any real stability there - e.g. cockerpoos bred to cockerpoos over several gens. A good breeder would know that.
Good for first time owners
You want something with a very stable temperament and that means buying it from someone who knows what they are doing (or a rescue from a reputable charity). Accidental or amatuer matings are a gamble for all sorts of reasons, but temperament is one of them. If you are buying a puppy, spend as much time researching the breeder as the breed. Be prepared to wait for the right one. It's worth it.
Be good with kids 8+
For puppies, this can be greatly influenced by how good the kids are with the dog. If yours don't know dogs very well then it's worth getting them around safe dogs now so they can learn etc. Plus keeping them engaged in the puppy's training - e.g. classes etc. It will help them relate to the dog as a dog, rather than a novelty, iyswim.
It would get (a minimum of) two 30 min walks a day during the week and much longer at the weekends
That's actually on the lower side of exercise for dogs. I only mention it because I think sometimes people think that level of exercise of normal and therefore must be moderate for the purposes of any breed description. You will want something with low exercise reqs. Lots of the companion breeds can fit into that category (dogs bred just to be companions vs bred for a job), so pugs, Cavaliers King Charles, Pekingese etc.
None of that answers your question directly, but hopefully is useful info?