Ryobi work light mods?

A friend of mine asked me for advice modding his Ryobi work lights. He has the old model:
http://www.cumminstools.com/browse.cfm/4,994.htm

and the newer model that's part of the new line of tools that use the new Ryobi lithium-ion battery:
http://www.ryobitools.com/lithium/
(click on the "TOOLS" link on the bottom of the page, then click on the 18V Worklight link near the upper right corner to see it)

I tried searching the forums and came up with a handful of threads that weren't too helpful. I also know about the TerraLux drop-in for the older model light. But my friend would like to take advantage of the new li-ion battery and really pump a lot more light of of his Ryobi worklights.

For the new li-ion powered Ryobi light, I guess a more powerful incan bulb or a (multi-)LED upgrade would do the trick.
For the older model Ryobi light, I'm thinking he might need/want to upgrade the battery pack first, since its ni-cad.

Thanks in advance for any help, ideas, and/or suggestions.

I have the Terralux cluster in my old-style Ryobi 18v light, and it works great. When the 4 nicads I have now have worn out, I'll replace them with the lithium batteries. It shouldn't take too long, since I have a drill, impact driver and small circular saw, in addition to the light, all running off the same batteries. Great tools.