I agree with Medicineman; you couldn't get an actual telescoping cyberlimb for that. It would be more of a cosmetic modfication, an extra 500 or 1,000 or whatever. It would fit with the extreme body mod fetish scene that they describe as one of the Shadowrun world's subcultures.
Cyberweapons? Sure, he could get a laser for about the same price and effect as the one you can get for the cybereye tool laser, or get the equivalent of an oral slasher, or a cybergland if he wants to keep with his chemical schtick. But none of it would be very practical, other than as an attack from an unexpected quarter against someone that the character already has in a compromising position.
I would be careful about these requests, though. These kind of jokes, while sophomoric, are fine if everyone just has a good laugh and that's the end of it. But be sure the character is more than just a joke concept who won't have anything constructive to do after the first session, and be sure that this won't disrupt your game too much. I have noticed that after the initial chuckle or eye-roll, such humor can rapidly become tedious.
