I don't know if there is anything else available but I found this tool.
http://www.chickensys.com/translator/translatormac.html
For instance it can convert akai, roland, emueos emue3, kurzweil, ensoniq, soundfont, giga, samplecell, s5k-mpc4k and mesa to sampletank.
http://www.chickensys.com/translator/tr ... lable.html
I would want to know if it allows the sounds to be modified as much as a normal sampletank sound. It would be good.