That 3 CREE LED light will be a lot bigger than your L2D. Which L2D do you have? You could try something that takes P60 style drop-ins as there are many Cree Q5 P60 stye drop-ins you can get. Like a Surefire 6P, G2, etc. I'd go with something metal as it can heat sink. I like my Dereelight CL1H V3, it has improvements that improve the heat sinking, which is important when you start pushing the Cree's hard. They make Q5 modules that run the emitter at 1.2A from a 18650 battery. With a smooth reflector it will really throw the light, and with an OP it will give you a larger hot spot and a cleaner beam.
You can see my review here:
http://www.candlepowerforums.com/vb/showthread.php?t=178042
Ordering info here:
http://www.cpfmarketplace.com/mp/showthread.php?t=170818
I'm still waiting on the new Dereelight Q5 WC 3-stage 1.2A module, I'll post an update when I get one. The nice thing about a light like this is when a better emitter comes out, you can just order the new module, rather than buying a whole new light.
Basically any of the Q5 lights running the Q5 at 1A-1.2A will be putting out around the same lumens, it's a matter of what kind of beam you want, floody, spot, inbetween. If you simply want throw then you'd want to look at the Dereelight DBS, Tiablo A9, Lumapower MRV, etc, but they will be larger than the L2D. Also the Dereelight CL1H will probably be shorter than the L2D, but a little thicker. Also it utilizes 18650 batteries, so you'd have to get set up with an 18650 battery and a charger, and most of use like AW's batteries which you can buy here:
http://www.cpfmarketplace.com/mp/showthread.php?t=170420
To get brighter than that you have to look at the multi-emitter lights, which generally means a larger light, although modders like Milky are putting multiple Rebel LED's in hosts like Surefire U2's which are probably putting out 400-500 lumens! Of course going that route will mean spending a lot more money as well.