Just to add, I would be happy to look at sorting this out for ISC (and sign the resulting package correctly so it will work with GateKeeper). My rates are very reasonable!

I think best practice these days is to embed the JRE with the Java app into a Mac OS X application package:

https://docs.oracle.com/javase/7/docs/technotes/guides/jweb/packagingApp...

This avoids problems with different Java runtime versions (at the cost of a little bit of disk space).

Any chance ISC could do this?

This might be of help as well:

http://blog.dadabeatnik.com/2013/02/04/bundling-a-jre-with-an-app/