A lot of cameras have in-camera panorama assist, which basically prompts you to overlap consecutive with frame lines or some other aid. The actual panorama is created on the PC at home. IIUC some cameras stitch panoramas in-camera, but I wouldn't fixate on them unless you don't plan on any image post-processing.
Find a camera with a wide angle lens (minimum 28mm equivalent, or wider if possible) for the best results (fewer images to stitch).
As to batteries, I'd look for a camera with good battery life (300-400+ images per charge per battery) and get some spares or have a charger in a drift box you send forward between resupply. Aftermarket spares are usually cheap and lightweight. There are still AA and AAA cameras, but few at the upper end of the market. Note that they require disposable lithium or NiMH, as alkalines give really poor performance.