Matrex 1.2 for MacOSX alternative setup

I've got some one reporting me that the Matrex 1.2 version for Mac OSX does not install perfectly on all Macs.
The problem is that sometimes after the setup Matrex does not look like an application but like a simple java folder.
Surely you can open a terminal and run the shell script (the batch file) from there, but this is not really an intuitive way of running it!

I use IzPack to install my software and IzPack claims to be able to install also on Mac OSX, even if from some messages in mailing lists it seems that there could be some problems.

I tried to see what I can do.

First I will modify the shell script so that it can be called from everywhere (an initial statement to let it use the current directory as starting directory).
Then I will update Izpack to the last version (3.11).

But one thing that I would really like to do is to create a MacOSX application bundle containing the Matrex files.
The application bundle is the natural way applications are installed on MacOSX.
To do this you need:

• a .icns file, that contains the application icon.
  
• a way to generate a .dmg file, which is an autoinstalling disk image containing the application bundle.
  

There is no way, as far as I know, to generate .icns and .dmg files outside MacOSX.

So, if someone has a Mac and wants to help me to build this application bundle and to test it, can he please let me know?