cool idea. keep us updated please. If you need to sound off ideas or have a question, feel free to ask.
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Imalent infinitely variable tint light: SA04 Review here and here
one of ttrev3’s latest posts (headlamps): https://budgetlightforum.com/t/-/28142
If you are looking for primary/rechargable battery compatibility, the spark SX5 battery container comes to mind.
If you are seriously considering RBG (W) in your light, the XM-L color has almost everything you are asking for.
If you are going to push high currents through the LED, I recommend a noctigon direct thermal copper board, or a sinkpad. The cooler the led are, the more efficient they are.
a smaller led die will “throw” light farther than a larger led die with the same reflector. eg. cree xp-e vs cree xm-l.
mtn electronics has really good prices, is US based, and is a user on this forum (username: RMM)
illumination supply (user: Calvin-IS) is also a very good online store.