I just fixed my Kmail+GPG problem. Seems I had a typo (or 3) in my fink.conf file, so the unstable ports weren't being searched. Kmail required gpgme for GPG integration, and it's only available in unstable. With the correct package search paths, the pre-built KDE binaries work just fine using gpgme.
Despite a healthy serving of crow, I'm now quite happy with the arrangement. Mail is my primary window to a lot of things, so having my mail the way I like it is important to me. Nice to know that OS X cooperates.