Advice for a newbie please

I am just about to embark on my first mod to a flashlight.
I have several candidates, mostly incans, one in particular is a 6v lantern type torch, but it's output is laughable, it's a Nightsearcher Puma.
It has absolutely nothing going for it other than, it's big so can take a decent size/combo of battery, the head is about 105mm, and focus able.
I am good at making things, have a lathe, so was thinking of several SSC P7-C leds, think I could get four in there.
The "pill" as people call them that is the controller right ?, so I would need one of these, as I want only high and low mode say 1 on, on low, all 4 on on high, is this doable ?
Any advice most appreciated, would I be better of keeping the lead acid battery it already has ?
Thanks for any input and sorry it's so long winded.
tabetha

Just had a look at the Nightsearcher site, it appears that the Puma
has a plastic body ?
I dont think putting multiple P7s in a plastic bodied light is a good idea.
You need a metal bodied light so that it will act as a heatsink and draw
the heat away from the emitters.

Why not put a HID setup in the light ?

Hi,
I did think about that, but only thing putting me off is cost.
I can lathe up a heatsink alloy plate for it all to go on, even with fins.
Just annoys me that for the money and what I was led to believe it is crap in performance terms, I wanted a long run low mode, maybe some diff led's might be better.
I even bought a new DX H3 led bulb, but not bright enough at all really.
tabetha