There are a number of military, parapublic and commercial operators using the Sea King and commercial derivatives for fire fighting. There are a couple of different approved tank systems, in addition to the various bucket systems. It is interesting to see the military use the Simms buckets, as they have never been seriously used by commercial operators - who spend a major part of their lives fighting fires.
All commercial operations are conducted using bubble windows (or no windows, when it is hot). I have previously posted a number of picture of the Carson machines with tanks and they can be installed on any variant of Sea King/S61 except the "L" model - due to hull configuration.
If you want more information on configuring a machine, feel free to contact me. If you have the time and motivation, come to the Sea King Symposium at the end of the month and there will be a whole buch of people there who can tell you anything you might want to know!