Before I make purchases I want to consult the genius mind trust at cpf...

Would 2 x18650 with a lfp7 be a wise choice for my m6? Looking for 6-8 hundred lumens, 1 or more hrs, tight spot if possible, oh, and I have to be able to pound tent stakes with it.

I am new at this, obviously, your country thanks you for you input.

I'm not sure if a lumens factory P7 head can handle the abuse of hammering tent spikes into the ground. LF makes a good product, but I'm not sure the electronics are potted. I suggest using your axe for the tent pegs

if you just want the option to be able to use your flashlight as a hammer if need be, a stock Surefire Fury tactical may do the trick. Most lights that are built to handle the recoil of a rifle, should have there electronics potted, and a head spring to prevent battery damage.

If your going to hammer in stakes, put both your leather gloves over the light, it'll soften the blow and help the aluminum body to last longer.

Malkoff MD60 drop in for the M6.
Fits the output requirement and the ruggedness requirement. Made to drop in to that light. Fully regulated at the voltage range you specified .
It's out of stock right now, but if you watch the Malkoff website for a while, it will be back in stock. Or subscribe to the waiting list for that product on the Malkoff site, and you will be notified when it comes back into stock.
Also ten bucks cheaper than the LF P7 head, and has the latest XM-L2 emitter.

I don't own any 18650 lights, but when you say hammer I think Fenix TK20, which they don't make anymore.

They do however make TK22s, and they have those dual spring setups, and can take an 18650.