you should always have more than one litter box and more than one water bowl for the cats. It doesnt matter if u get a male or a female kitten, just take it slow but give them both lots of love and if u see them fighting, break it up quick and give them lots of petting and love. Sooner than later they will be fine, i didnt use another room or anything, and at like i said the older cat kinda got frisky but in a few days they started to become friends,,,remember in a cats life, food and treats and love play a big role,,look at old ladies they have like 20 cats and they all just want food and love and treats and a warm place to sleep. Sometimes cats wont be that good of friends and U will play the biggest role in there life. My cats are 2 different breeds so they dont always get along but if i am around, one or the other will always want there face or neck scratched. As long as u r a good owner, the cats just want a warm place to sleep , treats and love and food and water and clean litter.