So, I got tomcat running in the cloud. And it turned out I do not need Sun's java; the opensource or whatever there is is enough.

I actually do not even need an s3. Will pipe through my website:
- an ftp script on my laptop that sends a new .war file if there's any;
- an ftp script on the ec2 instance that will pull the .war and deploys it in tomcat;

Probably just one question left, how to translate 80→8080; the suggested solution somehow did not work. Oh, whatever, it's not the most important. Just make it work.