Hi Tonya!
What an absolutely BEAUTIFUL kitty! I hope you do decide to adopt him!
As you probably know, I have a pet Turtle, Yertle, who has been with me for almost eleven years. He doesn't have a tank; he just roams the apartment as he pleases.
When I got my kitties, I was very concerned for Yertle, as a kitty can do a lot of damage to a turtle! Elvis was about
2 - 2 1/2 years old and Danny was 6mos - 1year when I adopted them. I expalined to the lady at the shelter that I would only be bringing one or both of the cats back if they posed a threat to my dear, sweet Yertle, although I had not had a problem at all with Charlie, my previous kitty (Charlie was 6mos when I adopted him). The idea of taking a kitty back to the shelter was devastating, but I had to be realistic and honest with myself and the people at the shelter.
I kept Yertle in the other room while I gave the kitties a few days to get used to their new home. After several days, I began bringing Yertle out every night when I got home from work and letting them have some supervised time together. In the very beginning, though, I always held Yertle close to my chest, sat on the floor and talked soothingly to all three of them. I wanted the kitties to get the idea that I loved Yertle and that all of us had to love Yertle. I also wanted Yertle to feel safe. I had done this with Charlie and it worked nicely.
Anyway, I only began to allow Yertle out of the room during the day when I wasn't around when I felt that the curiosity had died down. The kitties were no longer sitting around staring at Yertle and Yertle seemed comfortable around them.
Now, everything is fine and the three of them cohabitate peacefully.
I realize that a bunny is much different from a turtle, but I think that, as long as you take the time (and I know that you will! ) to introduce them slowly and give them time to feel comfortable with each other, they will be fine!
One thing I would say is, if you do decide to take this kitty or another "older" kitty, try to find out from the shelter how he interacts with other animals. I am sure that you know this, since I know that you have had cats before, but this is really the key.
We wish you the best of luck, and please let us know what happens!