Soundfont decompression utilities Options

I'm looking for MAC soundfont decompression utilities for .SBK and .sfArk formats. There is one available for .rar files, and those that are compressed in .zip are no problem, but I can't find the others. I convert the soundfonts (using the SF2 FileTyper that comes with Unity) and use them with Unity DS-1 and Digital Performer 3. If anyone has found them, I'd appreciate hearing about it! Thanks!

Here's some soundfont info:

This is the best source for soundfonts that I have found, but they are uncompressed, so download is lengthy:
http://www.thesoundsite.net/sf_uc_dirlist.tml

You can find lots of free sources by doing a search for 'soundfonts' or 'sf2'

Good source of multisampled instruments (soundfonts) for purchase:
http://www.sonomic.com/

For compression tools, this is a great place to go:
http://www.gromwin.demon.co.uk/vanessa/compress.htm

So far, I've only had success with uncompressed files, .zip files and .rar files. There is about a 10% error rate in file translation to Mac format. I suspect that all of them are not done to standard. I open them in Unity DS-1 and export them as native files. I've been able to accumulate over a Gigabyte of sounds by doing this. You can also find CDs of soundfont samples for purchase that will vary greatly in price. I'd check out the free stuff first. I've purchased some, and the quality is no better or worse than the free stuff.

Gool luck!

Wynn