Hi,
with DP 8.XX the Java-GUI became obsolete and is no longer delivered. So in your case use the Windows GUI instead. The push installation will work the same for you Linux based clients. Just import the installation server, enable ssh in omnirc on your Linux installation server and exchange the keys between your IS and clients. After that you are able to diustribute the Linux based clients the same way, as it was with the Java GUI.
Best regards
Daniel