I Never Thought I Would, Need Advice introducing new kitten Options

[Shortrish]

Well, I've gone and done it. I started going to the local shelter 1 week ago, just to give love to the cats there that were homeless. I kind of was drawn to 2 cats. One was a majestic 13 year old cat named Mookie. There was just somthing in his eyes. Maybe it was because he was old and I figured no one would want him. The last time I visited him, he had that upper respiratory infection that cats get, and his one eye was very red. He didn't seem too strong either, but he let me pet him.
When I called and asked about him the next day they said he was very sick and in isolation. So, I went with my husband to visit little Marcel. He's a little male, neutered, has had some of his shots and has had a microchip inplanted already too. They neuter and chip them before any cat gets adopted from there now.
He seems healthy and full of mischief and very active. Well, we adopted the little guy Sunday. I am still crying over Scooter, but have hope that this new little guy will help me heal. He certainly does keep me busy.
I feel guilty though. Does anyone have any advice on how to help my 3 other cats adjust. They have just barely gotten over the loss of Scooter, when here I bring a new one into the mix. We keep Marcel in his own separate room with everything he needs. Boo, the oldest cat, is upset, and Fidget as well, Gabbie growls and makes this huffing noise. I wonder what on earth have I done to my 3 other cats?
I really want this to work out, but it's been awhile since I've had a newbie around.
How should I handle my 3 other cats? Is their reaction normal?
When Marcel sits still for a moment or two, I'll take a picture to post here so you can see what a cutie he is. He loves to cuddle, and run and flip out and play, just like a normal healthy kittie should.
Scooter - this little guy in no way ever could replace you, and we did not get him to replace you ever. Our hearts are filled with the love you gave us, and you have left a hole in our hearts so big. We love you and miss you so much.

[Simba's Daddy]

I have never know any animal to "immediately" take kindly to another one introduced into the home. I am sure in time they will all get along though and the new kitty will help the others heal from their loss as well as you. Just give it some time and let it happen on it's own. I bet they are playfully chasing each other around soon

[Ken Albin]

PLease see my response to "Found Kitten" in the "Lost and Missing" section. It is based upon 10 years of hard experience and discussions with successful cat rehab people and vets.

Good luck with the bonding,
Ken Albin

[Shortrish]

Thanks Ken - I'll give those steps a try. I know with cats it does take time. I'll let you know how it goes.
Trish