For anyone curious, like I was, the the 4x 1/3A 4.8v batteries DO fit the GGTB. The GGTB is rather finicky about what batteries will fit in it (only accepting AW 17670's and not Ultrafire 17670's due to tight tolerances), but I took the chance anyway.
You can get these batteries at madvapes or electronicstix. I got them from the former, but he does not have chargers yet, and last I checked, electronicstix was sold out of the chargers.
You can get these batteries at madvapes or electronicstix. I got them from the former, but he does not have chargers yet, and last I checked, electronicstix was sold out of the chargers.