We have a generic domestic short-haired. She's very self-maintaining. If this is your first foray into cat ownership, I'd go for that.
We do have a pedigree Persian that came to us as a stray, but he is much more high-maintenance and needs some more expensive treatments such as regular teeth cleaning and professional grooming b/c of his breed.
Our cats are placed in the living room to sleep at night and we shut the door on them.
Another tip for training is to get a spray bottle and fill it with ordinary tap water. If kitty is found misbehaving, simply give him/her a squirt. On the body ONLY, never the face. He/she will learn quickly that such behaviour is unacceptable.
Kittens are in much higher demand that cats who have grown. Which means more cats who are grown are sadly having to be destroyed.
Some advantages to having an older cat - even a year old, for example - is that they have a better developed personality, so you can tell already if they'll be good w/kids, mix well w/other cats/pets, behavioural problems will already be evident, as will any health conditions or special dietary needs the animal may have.