What Age Should I Get My Kitten Neutered?

I am thinking about getting my kitten neutered. I have read that it is easier to get your male cat fixed before he can father his own kittens, but what are the disadvantages of doing this? Is it really harder to take care of a partially neutered male cat than one that has never been fixed? Are there any other benefits to having him neutered at an early age?

Also, if you do find out you want another kitty in the future, will they be able to tell if your current kitty has already had babies or not by their behavior when reintroduced into the world again after being fixed/neutered? If so would that mean I need 2 males or just 1 for when things go awry with my current kitty’s littermates in the future? Or does it only matter when considering which cats are suitable mates once more kittens are born from them?