Electrical short

I have a 96 chrysler sebring jxi convertable with the v6. It appears as if the body drains might have plugged up and water flooded the floor pan. The speakers quit and a week later a fuse blew. I replaced the fuse for the radio. Then the car alarm would not allow me to start the car as it would activate every time I turn on the ignition. I took the car to a dealer and they stated after 800 dollars labor they don't know what is wrong but they think it is the module/amplifier part# z4608313. They are telling me the part is no longer available and this car is now un repairable. I know enough about cars to feel I am being taken for a ride. Please tell me if you know of a replacement part and or if you think the problem is related to something different. I would like to be able to at least be able to get the car running and driveable. Thanks