@OP: Your expectations are rather high… 100k lumens for two hours at 100 feet, especially for a waterproof-dive light and all that it involves. I’m no expert but this seems to me a very special equipment (non mainstream) that certainly requires serious R&D for a very small market.
Either you are prepared to pay a stiff price for it, or spend a lot of time doing your own R&D… You won’t find an easy and cheap solution IMO.