Other than trashing the Font Book application and plist is there anything else that I can jetison?
You can go to the ~/Library/FontCollections/ folder and empty it. If you were to ever put Font Book back on your Mac, it will recreate the basic font sets.
The main thing you will need to do is move all of the fonts in the /Library/Fonts/ folder and the ~/Library/Fonts/ folder (the one in your user account) to a new location, or they will always be "on". Suitcase Fusion, FontAgent Pro and Master Juggler cannot control those folders. On the other hand, FontExplorer X can enable and disable fonts in those folders, so there would be no need to move them.
FontExplorer X is free and can be set up to behave either like Suitcase Fusion (activate fonts in place), or like FontAgent Pro (copies all fonts to a working folder in your user account). Suitcase Fusion and FontAgent Pro have 30 day fully functional trial software you can download from their sites. I personally cannot recommend Master Juggler. It's a solid, stable font manager, but has numerous design flaws that make it unusable.