I really dislike munchkins just like how I dislike flat-faced cats: I don't want to introduce problems cats normally wouldn't have to cats. Nature has already made them perfect!!!!
If you want a shelter cat, you probably don't want to be thinking of a breed anyway. Unless it's very common where you live for people to abandon their potentially very expensive pedigree cats. Sometimes cats (and other animals) are abandoned because they have issues, so you should try to figure out why that particular cat got there in the first place.
Sounds like you probably want a pretty low energy cat that is affectionate. It can be hard to properly see how affectionate a cat would be in shelter conditions where there's lots of people who might not be able to spend a lot of time with the cats to socialize, but if there's a particular cat that likes to greet and hang out with with the humans that do come to look at them, that might be a good place to start searching.
Though many cats will start being different once you earn their trust. Also, if you start looking for younger cats, remember that 4 months is around the time when any respectable breeder would give out their kittens. Avoid anyone that is willing to give you cats when they're like, say, 8 weeks old. Or EDUCATE them if they're not breeders and they had whoopsie babies and have no idea about cats.