I recently bought a kitten for the very first time. I bought a Russian Blue. I always admired that breed -- but I was unsure, as you are. I'd always adopted kittens from the humane society before.
I did a lot of research online! One thing that I learned is that you are actually assuring yourself of getting a healthier animal temperment wise, if you go with a reputable breeder because cats at the humane society are often inbred -- on the street, nobody is making sure that cousins don't breed with cousins and mothers don't breed with sons etc.
Anyway. My dip into the pedigree world was a huge success. I love my cat. He is such a complete and utter darling. So very loving! But no different from the other lovely cats that I adopted from the humane society -- cats are cats are cats, in that sense.
I guess I felt guilty about picking a kitten just for his looks, rather than giving a needy animal a home. There's almost a whole 'modeling' agency thing surrounding the whole breeder's world -- like looks are all that matters (because breeders are rearing animals in order to win medals in shows). A reputable breeder, though, will care more about the health and happiness of her cats than their success in the ring.
The main thing that I learned in my research -- the importance of going through a reputable breeder and cattery.
Also, if you can visit the cattery first or attend shows -- it really gives a good idea of what the purebred world is like.