You are correct, the FAMAS Surbaisse seems to refer to the rifles with the lower carry handle, while the ones with the FELIN integration are just known as the "FAMAS FELIN". Four types of FAMAS (FAMAS F1, FAMAS Infanterie, FAMAS Surbaisse, FAMAS FELIN) can be seen among the units participating in Operation Sangaris.
Here's an example of the FAMAS Surbaisse:
