Only get one that is old enough to be de clawed or already is...de claw all 4's, I really wish I did the back ones with mine.
Prepare to clean up puke/hairballs now and then, so invest in carpet cleaner. Prepare for the cat to ignore you when you don't want it to. Some cats get problems...like we had one that kept peeing or pooping on the couch suddenly, wasn't urine tract infection either, the vet couldn't figure it out other than to say he must be stressed somehow, a year later or so he finally stopped, again for no reason.
Only thing I hate the most is how they get cat litter on their feet when they walk out of the catbox and it gets all over the place, no kitty mat works that well cause they like to run or walk swiftly out of there.