I think in the long term you will be much better off with getting something like Keyclone as you will find it extemely annoying moving from window to window.

That being said, maximizer is available as a standalone from http://wow.curse.com/downloads/details/146/. You should note however that if you use a resolution ratio other than 4:3, your wow windows may stretch which just looks bad, this is assuming that you want your windows to fill the screen. There is a file in the Root Folder of Wow that I think is called config.wtf or something simular. Edit this in notebad and find the resolution setting. Change it to match half of your resolution. ie, if you are running 1024*768, you would change it to 1024*384 for a top/bottom layout or 512*768 for a left right layout.