Woot!
The one downside to the Lite sound - you're going to go through batteries, and they "fade", something the buck puck prevents in the LiIon setups.
I recommend a double set of "normal" recharging AAA batteries. That way you can swap them out at need and always have fresh batteries. :-)
And don't skimp on the rechargeable batteries, either. Get Eneloop or Eneloop Pro batteries. I've tried several widely-available brands, including these, Amazon Basics, Energizer, Tenergy, and others, and while any of them will save you money over alkaline batteries, I'm holding out for Eneloops from now on.
Also, you'll do better to get a charger that has a separate channel for each cell, rather than one that averages out the current/voltage across all 4 cells.