If you're going to change the camera you'll also need to change the monitor. The good folks at www.rvcams.com
have everything you'll need.
I changed my monitor about a year ago but have not done the camera yet. The color camera fits exactly where the old one was in the same bracket. The monitor bracket that comes with the kit is bare metal. I painted it black to it's not quite so out of place.
Your existing wires will work and it's a very easy install. Feel free to PM me if you need more information.