Is it possible to only allow root access from certain ip addresses of my choice, I think might be the best way to avoid to hackers.

Yes, using PAM:

http://www.101com.com/solutions/security/article.asp?ArticleID=528

Hope to god a piece of your equipment doesn't fail, and your IP gets changed. If your going to do that, Id recommend installe SUDO first. It allows SU commands that you specify from certain users.. Its nice, check it out.