Glad that you found a fix for your challenger. Unfortunately all protected batteries I've encountered have been different lengths, as the protection circuit takes up some space in addition to the standard battery.
This calculator might be useful for you:
Relative Laser Beam Brightness Calculator: (445nm 2000mw) vs. (532nm 198.51mw)
You can see that 200mW of 532 green is equal to 2W of 445 blue. 532 or 520 are your best options. Sanwu and jetlasers have some high quality options. For $200 jetlasers will...