Female or Male?
Provided they are neutered, it doesn't make any difference, as both males and females make wonderful and superb pets. The key difference is size - male cats are almost always larger than females. As far as the character and temper are concerned, all cats are individual, and it is difficult to make any generalizations. However, males seem to be more lazy and relaxed, certainly I'm talking all the time about the castrated ones. Your choice of sex may also be determined by the cats you already have at home. For example, if the cat you have is a nervous and not self-confident one, he or she could feel intimidated by a huge male coming into his or her territory, so you'd better bring in a kitten.
Choosing a cat.
Mixed kittens are often homed around the age of eight weeks, but pure bred kittens do not leave the breeder until 12 weeks, and in the USA between 14 and 16 weeks. This extra time means the breeder can ensure all the kittens have received their primary vaccinations, can be litter trained, and be properly socialized. The importance of socialization cannot be underestimated. Socialization involves introducing the kitten to everyday life - its smells and sounds, and prepares the kitten for the future. Therefore it is very important to find a breeder that has a lifestyle very similar to your own. If you have children, find a breeder that has kids of the same age group. If you have a dog, choose a breeder that has one, too.
With shelter cats, the kittens' past is often not known. However, as these kittens are rehomed earlier than breeders' cats, you will have the opportunity to be responsible for your kitten's early socialization, while she is still young and receptive to new experiences.
Check if the cat you have chosen is healthy:
Asses the kitten's size. A larger kitten is likely to be heathier and stronger.
Watch the kitten move, to to check if there isn't any limp in any of the limbs.
Look into the kitten's eyes - they should be clean, without any reddenings. The presence of a third eyelid accross the eye usually indicates illness.
The kitten's ears should be clean. Any redness, dark wax or odour can indicate mites or an infection.
The nose should be slightly moist with no discharge.
The kitten's gums should be a healthy pink, and the teeth should be white and clean.
The breeder should also give you the pedigree, vaccination certificate, details of worming treatments, a receipt for the amount you paid, and a diet outline.
You should also assess whether it is safe for you to have a cat. If you live near a busy road, you can only consider having a house-cat. This will limit your choice to a kitten, to a breed or mixed-breed that was born and is accustomed to indoor life, or to a shelter cat that previously lived as a house-cat.