I've played MT-32 files through MegaMID. Err... Hmm... I don't know for sure that it does send MT 32 sysex commands, though. I know that it does send other sysex commands, though. It's also neat because you can goof with instruments on the fly-- you can't queue up midi files in the windows version, though :-(
I am gonna give VanBasco a shot, too, though.