I would personally say perl would be the language for you to pick up. (I am partial to perl though.)

It will also help you with your admining.

To set up a script that goes off when the server goes down, you need to know what happens to get your server to go down. Once you know that, you shouldn't need a script, because you should start working on fixing what is taking your server down.

If you tell me what the file is that takes your server down, I will write a little script that will run in the background, and let you know if your server is acting stupid/has gone down.