I've had a short fic character whose guns have been described as "Morissey-Kimber" (just stock Morissey guns, but with 'pimped' bought and acting like it came standard) for a while, now.
There's certainly plenty of room in Shadowrun for it, but I've always been a big fan of doing that sort of thing with cars, guns, etc, anyways. Just change the name of something, call it what you want to call it that you think is cooler, and call it a day.