Get a rescue, not a posh cat.
Lots of unwanted cats are euthanised every year.
Kittens are cute, but they only look teenie and adorable like that for 5 months or so.
With an slightly older cat (say 1 or 2 years) they have a more developed personality and it will be easier to tell if they will fit with your family or not. You cannot train a kitten to have the personality you desire, for the most part.
'Form' (breed standards) is only necessary if you're going to show. Many of these for certain breeds can increase the likelihood of serious ongoing health complaints. If you are interested in a certain breed, have you even bothered to look up breed standards for it to see how much money it may cost you in vet fees above the usual cat problems?
As for temperament, it's mostly a load of arse. Cats are mostly too genetically similar to have set temperaments across any one breed. The only exceptions I'd say would be Siamese, Burmese, Maine Coon, Ragdoll having certain temperaments, but that's purely down to my own personal experience of these breeds and is not scientific fact. There also may be health issues involved that produce particular temperaments.
If you want something pretty to look at, get a nice picture or a sculpture.