2010 CX-9 Radio issues

I bought a used 2010 CX-9. I've had her 35 days and the other day the radio emitted a high pitched noise and blew the ROOM fuse which I replaced.

Now, when I turn the radio on I hear the high pitched noise and shut it off before the fuse pops. It is a plain jane radio, no nav, no back up camera just a single CD, plain Jane. I'm not sure if it is the amp or the radio any help would be greatly appreciated.

Also I've read replacing the radio might make the AC not work so if I do replace it what do I need to look for? What radios will work
I want a nav/radio/CD or DVD type deal.

I also want to install a back up cam for the wife, if she drives it.