I'd personally recommend using a font manager for this kind of thing.
They allow you to group your fonts into "families", e.g. Rounded Fonts, Handwriting, Spooky, Futuristic, etc. They also give you previews and all sorts of other "fonty goodness".
It can take some time depending on how many fonts you have - for hundreds it can take a few hours - but once it's done it'll save you a whole boat-load of time in the future. (And you'll probably see fonts that you never even knew existed on your machine that give you ideas for other projects.)
Font managers are usually very small applications so they don't take up much extra memory if you've got one running along with Scribus.
On OS X you can use "Font Book" (installed as standard in Applications).
For Windows and Linux I'm sure there are loads of similar applications and someone else will be able to advise better in those cases.
A search for "free font manager" will give you more options than you can shake a stick at (please don't shake sticks in enclosed spaces

).