Honestly going with a camera with its own special charger isn't going to add a lot of weight and space, but it will save you some decent cash in the long run. Even carrying an extra set of batteries for the camera is adding up weight/space, close to the chargers weight. AA based P&S cameras are pretty bad on batteries overall, not to mention the models are really nothing....

Don't know if this is worth commenting on or not if the OP already owns one.... Some DSLR can take AA batteries using a grip.