If/when to find a companion for my 13-year-old neutered male?

Question:
 I just lost one of my two constant companions of thirteen years.  I adopted littermates Holmes and Watson when they were kittens. Holmes was a calico, the alpha kitty, and very protective and maternal towards Watson.  They were inseparable and he (and I!) are quite devastated by her loss. In addition, I've taken a new job which has added a four-hour daily commute to my life.  I worry about Watson being alone so much of the time when he's had a constant companion as long as either of us can remember.  I'm certainly trying to avoid extra hours at the office and pay a lot of attention to him when I get home, but I'm beginning to think that I may need to introduce a new cat sooner than later.  He still runs to the door mewing if one of the neighbor's calico cats comes up on our porch... Watson may be getting to be a senior gentleman, but he is still very much a kitten in temperament.  He is very docile and easily intimidated.  I don't want him to feel threatened by a new addition, but would like for him to have a playmate.  I'm leaning towards a younger adult female. Any suggestions? It's not even been a week since we lost Holmes and I want to allow us both some grieving time.  What might be an appropriate time frame for introducing a new cat?  Is another female kitty the best option?  Another calico or someone with potentially a less assertive personality? Are two shy cats a good match?  Watson is very outgoing with humans, but was very much frightened by a female kitten I fostered a few years ago. Again, any thoughts/suggestions would be appreciated!
Answer:
 whatever you decide to do, if you do get another cat, take it slowly. Start by keeping the two cats in separate rooms. Take a cloth and rub it round one cat's face, cheeks and body, and go into the other cat's room and rub the cloth up chair legs, door frames and so on. Then do the same with that cat, spreading his/her scent into the other cat's room. Do this for a week or two, or until each cat seems comfortable with being able to smell the other cat. Then you can try and introduce them. It should be a lot easier, as they will already be accustomed to the other one's scent. Whatever you do, don't just throw them together and hope for the best - it can go either way. I did that when we got our youngest (6 yrs, found her at 5 months under the car) and it was dicey, lots of hissing (we had two 12 yr olds at the time). Then she settled in, albeit still a bit grumbly today - incidentally, she went that way when the alpha sister died two years back. A year ago two more cats came (brother moved back in), and we just let them get on with it - and it has been no end of trouble. the oldest cat is fine, and they are with her, but the youngest (well, now the middle cat!) absolutely hates them - and vice versa. All day and night you can almost constantly hear her growling at one or other, and it only stops when I let them outside and shut the door. Winter will be very hard! Sorry if that went on a bit, I just wanted to give examples of what can go wrong if you try to rush things. oh, and one other thing - keep any new cats indoors for at least a fortnight to let them get used to their new surroundings, or they might run off!
Answer:
 If your cats stays indoor then the most important thing which you can do is provide him with entertainment. The older a cat gets the more it will sleep, the average cats sleeps for about 15hrs a day. The introduction of a new cat can be very stressful for both you and your cat. I would buy him one of those cat centres which he can play on whilst you are out and carry on playing with him when you get home like you are. I think he will be much happier with this.