Natural Satellites Orbital Elements

Hi All,
I'm the author of a Celestial Mechanics software
(http://orsa.sf.net), and I'm looking for a good source for the
orbital elements of all the known natural satellites in the Solar
System. A good source would be a downloadable ascii file, updated by
some institution from time to time, containing the name of the
satellite, parent planet, orbital elements and epoch. The orbital
elements have to be accurate enough to allow precise numerical
integrations, and not 'mean' values. I've tried to find something
similar around the net in the last week, without success.
Thanks for your time.
Pasquale