I can not decide if it is easier or harder to choose a cat than a dog. Most people do not choose to have pedigree cats, most choose good ol moggies. Most moggies are not intentionally bred, so with a dog you need to think about history, pedigree, inherited illness, mum, dad etc. With a moggie, it is likely you get told, here is mum, dad may have been a fat hairy tom we saw hanging around for a few days!
The first consideration is whether you should get a rescue adult or a kitten? Are you able to cope with a kitten climbing your curtains? As with dogs, you have all the expenses to consider with cats, but there is no dog walker needed, you can get someone to nip in and feed them if you go away, what other things do you think you need to think about when choosing a new cat or kitten?