i have 2 males right now and i luuuuuurve them.
here's my advice:
go to the pound, or a petsmart and spend some time checking the kittens out. first find one that you think is cute, then hold it. if the kitty seems really sleepy or insanely crazy, don't pay attention to it. they have been locked in a cage for most of their little lives and they all react differently to it. what you really want to look for is a kitty that purrs when you pet it. also, one that lets you touch it's belly without scratching the fuck out of you is good. this means that they are comfortable with you and in their surroundings. a kitty's belly is their weak spot. they won't show it to you or let you touch it unless they feel comfy with you.
make sure the kitten has been tested negative for fiv and feline leukemia. this is very important, especially if you ever plan on getting another cat.
check it's ears and ask if the kitty has been wormed or has had any of it's shots. if you see a buttload of black stuff in it's ears, the baby has ear mites. those can be a pain in the butt to get rid of. the medicine that the vet gives the cat isn't expensive, but sometimes they just keep coming back and you find yourself constantly having to clean out the poor things ears with mineral oil. cats usually don't have worms unless they've had fleas...at least not tapeworm, as that is how most cats get tapeworm. NASTY FLEAS.
kitten shots cost me around $80 total, but i go to a kind of expensive vet because i know he's good. there's usually a first round, a second round about a month later, and then they are good for a year. spay/neutering should be done around 4 to 5 months (and yes, as early as possible in males because they tend to spray). it cost me about $60, to get my one cat neutered. petsmart will give you a certificate to get it done for free, as will most animal protective leagues.
DO NOT DECLAW YOUR KITTY. PLEASE. I'M BEGGING YOU. IT IS INSANELY INHUMANE AND PAINFUL AND CAN LEAD TO YOUR CAT ACTING OUT IN DIFFERENT WAYS SUCH AS BITING. i solve the problem of the cats scratching stuff by keeping their scratching limited to one area. i don't have a scratching post yet, but i have an old beat up chair. i let them scratch the shit out of that thing. if they go to scratch anything else, they get yelled at.
i don't think the breed really matters. i've had many different types of cats and they've all been good animals. it's all in how you treat them. the one thing that i do know is that siamese kitties are very vocal, which can be cute or annoying, depending on how you feel about that.
oh yes, and i haven't noticed anything about males being more affectionate than females. like i said, i have 2 males right now. one is extremely affectionate and one only wants to play fetch ALL THE TIME. you met the last 3 cats i had. they were all females. one was super affectionate, one was insane and one was aloof.
i hope i helped some.