As this is a really old topic, most of the information is outdated on it.
What exactly are you trying to make work?
The kits that come from SF for the ASP come with LED, battery/battery holder, switch, and soundboard (if you want sound... if you don't, then go for a warrior kit). They're pre-wired with quick connects, so if you watch the ASP video (its linked in the ASP forum) you'll note it's very easy to slide them into a hilt, plug them in, and that's it.
If you're JUST looking for a 12W led, they sell those either with quick connects or without.
If you just want a stunt saber and already have the rest of the internals, just make sure the battery pack will supply enough juice to run the LED. You can either put quick connects on them as well or solder the LED to your power supply.