New puppy and resident cat introductions?

[rodeowiildone]

This is still awhile off, but I wanted to post this before I definitely decide to bring home a new puppy.
Around December of this year, I will most likely be bringing home a female Papillon puppy.
I own a 6 year old male cat and he is the king of the house. He is very loved and is extremely attached to me. He follows me around the house like a dog, meets me at the door when I get home, and sleeps on my bed every night (most of the time right next to me).
What would be the best way to go about introducing a new puppy to him? The last thing I would want would be to push him away and break the connection we have, but I don't want to have to sacrifice getting a dog. I'll be moving out in the next 2 years or so and I'm not sure if just the dog, or both, will be coming with me.
The cat is declawed on his front paws and is neutered.
We have a house with 3 floors. The cat box and his food/water are in the 3rd floor bathroom. When I get the dog, I plan to have gates so that the cat can have the 2nd and 3rd floors to himself. He'll be able to jump the gates if he decides to visit the dog, or needs an escape route

 

[Samtastic]

I can't say I've had experience but I can tell you what I know:

I have a two and a half year old and he was a really lovely cat. We decided we wanted another cat to keep him company and so we got a 6 week old kitten. Since bringing our kitten home, our older cat has turned into a grump and nothing like he used to be. The cats are the same sex and I know thats not a great idea, so maybe try bringing an opposite sex dog home.

 

[SaraOrchard]

i just recently got a female puggle puppy, and i have a ten year old neutered large orange tabby.

Before introducing them i made sure my cat had many safe getaways out of puppy's reach such as; a cat tower, a bookshelf, tall table, shelves... ext. this way he would observe the puppy without being "in danger" in his eyes.
I also designated one shelf on the bookshelf for his food and water so he could eat safely.. and so the puppy wouldn't eat his food.

The introduction:
i let my cat hide hiss and do whatever he needed... and made sure to give him lots of attention.
After a few days of hiding my cat came out and him and the puppy both sleep on the bed with me.

patience is key.
also having them on either side of you and positive praise helped me.