I do NOT own a Mac or have FLAC files to catalog but did some research and came up with the following. Some of the ideas are overkill, but they work nonetheless. A Stereophile editor may be able to help you...according to what I've read I think they have Macs.

Toast 8 Titanium
Cataloging and tracking of burned discs contents
http://www.roxio.com/enu/products/toast/titanium/features.html

FileMaker Pro 8.5 Advanced
http://www.filemaker.com/products/fmp/index.html
http://www.filemaker.com/

AquaMinds NoteTaker
http://www.maccompanion.com/archives/july2005/Software/NoteTaker1.htm

Library Monkey 2.0.2
http://www.macupdate.com/info.php/id/15229/library-monkey

Cataloging tools for Mac
SEE: InCDius GH 2.0b16, Movie Collector 1.8
http://www.pure-mac.com/collect.html

Books 3.0.4
http://www.macupdate.com/info.php/id/12713/books