Zoomies love dedomed emitters. If you can solder, you can do it. Just soak the emitter and base in gasoline until the dome falls off. There is a good thread on it around here. You may want to first buy a XM-L2 U2 1A on copper. Dedome it and then swap it into your light.
Here is a great database for LED's created by RaceR86. The tabs for the different types of emitters are listed across the bottom of the spreadsheet: