Update: I've since found references to the XP-L/HI (~1200 lumen), the XP-L/HI (at 1883), the XHP50/50.2 (at 2546), and the XHP70/70.2 (at a whopping 4,292 lumen). I need to check out these options, although I believe my outstanding questions remain - in short, what items to purchase.

Update: I forgot to say thanks for the battery holder leads. I may use them on other projects. For this project, I plan on building a custom pack for whatever my capacity needs end up becoming. I didn't want to spend $45 for a replacement Black and Decker pack for my leaf blower. Instead, I spent $20 on (better than original) batteries and then $15 on the parts for a DIY battery terminal spot welder. Then I built my own pack to replace the batteries in the Black and Decker pack. I have the supplies to build whatever size pack I end up needing.