Well, for parts you'll need the 12w LED, the proper 18650 rechargeable battery to power it, and the proper battery holder. For tools, you'll need a decent soldering iron (not one of those under $10 ones; you and whatever you are working on will regret it), some good solder (Rosin core and a lead/tin mixture), and the knowledge on how to use them. Also, this will void your warranty.
It may just be easier to wait until the ASP system fully launches and pick up a warrior tier electronics kit. It'll come with the LED (and word on the street is the new 12w+ LEDs will have phased out the old 12w LEDs by then), a latching switch, the battery and battery holder, all attached wth quick connects, so no soldering required. There'll also be a Champion tier kit (same thing plus a soundboard, speaker, and a momentary switch), if you want to go all out.
EDIT: the battery is an 18650