Also the 11.1v 5000 and the 7.4v 8000 are really close to the same size.
7.4v 8000 137x44x26 at 365g
and
11.1v 5000 138x45x26 at 345g
Im thinking 6 cells would be best but I don't know much about what diffences in current draw will do besides heat. And im wondering what the diffeneces in run time would be.