Looking for light to modify

Im looking for a light to modify into a light head for a dive cannister light.
A C or D celled Mag is the most common to use but I am wondering if there is something else out there that could work as well or better.

Requirements.

Needs to have a large head. preferably something MR16 (50mm) or MR11 (35mm??) drop in compatible.
O ring sealed
Ability to change the lens to a thicker one (4mm+).
The switch will have to be removed. If its in the tail cap then it will be replaced by a cable gland. If its on the body then that section will have to be cut off and rethreaded/ glued into the head.
Is there a light where you can remove the body and screw the tail cap directly on to the head?

Don't know if this would work for you, but it came to mind as I read your question. Can't beat the price, and since you are modding it...........
http://www.cpfmarketplace.com/mp/showthread.php?t=184676
http://www.king-cart.com/cgi-bin/cart.cgi?store=elektrolumens&product=Miscellaneous+Products

Packhorse said:

Is there a light where you can remove the body and screw the tail cap directly on to the head?

Click to expand...

Well, A Mag tailcap fits into the head. It doesn't thread, but some epoxy in there and It would be nice.

Other than that, I'm not sure there's too much out there that's as big, moddable, and durable as the Mag.