welcome to the forums, johnwags.
The most important anti-hacking stpe you can take with a Wordpress blog is to update your Wordpress installation the minute a new version or patch is released. The "dark forces" jump all over blogs that use outdated code.
This kind of vigilance is the price we all pay for using any widely employed platform, and I doubt that any plug-in can work. The minute such a plug-in was available, the dark forces would be poking it for hackable areas. It wouldn't last any longer than any Wordpress version does.