To be fair Gaban unleashing lightning directly kind of suggests Sanji doesn't really need a long-range attack since he can simply get the same thing down the line (not like a blade is needed when it's lightning that's flying in a given direction).
I think Imu's kicks give a glimpse of what Sanji should be able to do and if Garp can produce shockwaves with fists, Sanji doing it with kicks is possible. I just can't imagine Sanji with lasers but rankyaku, shockwaves, what Gaban showed, any of those but lasers seem a bit too far from Sanji's style.