This is how I made my 5* R2 Maglite mod, which can be considered a budget mod, these are the costs:
5 Leds module from DX $33,65 (includes heatsink, leds, reflector and 5 modes driver, ok, almost everything)
2 18650 $10 or 6 AA Eneloops with 2x 3AA>D adapters from KD (work pretty well with 2,5A)
Maglite (D size) from $15 to 50 depending where you live
And thats all.. now you need to modify the module to fit in the maglite head. You will need to do two things: 1. grind the heatsink, and 2. make an adapter to fit the bulb tower of the flashlight.
1. Grinding the heatsink
Grind 1 mm of this part (first arrow) This ring has 3mm, it must have 1mm
Grind down this ring
2. Making an adaptor to fit the bulb tower of the flashlight.
You have to disolder the springs, and solder a head of a screw in the positive to make contact with the positive of the bulb, and use any round piece of metal with a hole to conect around the screw with the negative. Of course, they must be electrically isolated to each other. You can use any piece of rubber
Now you can paste the module into the head of the maglite with thermal glue, and screw until it contacts the tower (without the bulb.. of course..)
Batteries:
Anything of around 8 V will work (in theory, up to 8,4v), i use 2x 18650 with this adaptor (inserting the batteries in a 1in PVC pipe). With this combination the flashlight has a current consumption of:
2,6 A (high)
1 A (med)
0,5 A (low)
? Fast strobo
? S.O.S.
You can also use 6 Eneloops with this adaptors, they say it works at up to 1A, but works pretty well for me at 2,5A.
Other options are using 2 x 32600, or 2x26500.. whatever you like, and you can pay..
The leds will even work with 3 x D alcalines, which draw 0,5A in high.
I don't find more pictures now, but this is a video of the beamshot..
Original review in spanish in Forolinternas. I hope you understand my english :)