RE: water jets
You've got
[link=http://www.jet-drive.de/]KMB[/link]
[link=http://www.swashdrive.com.au/]Swashdrive[/link]
Gundert offers these
[link=http://www.gundert.de/ka30.htm]Gundert[/link]
and as Ron said
[link=http://www.shop.graupner.de/webapp/commerce/command/ExecMacro/Graupner/macros/main.d2w/report?lang=en&show_cat=5445]graupner[/link]
and finally
[link=http://www.mhz-engines.com/]MHZ[/link]
These are what I am aware of, maybe more.............