I have every intention of making a carbine myself, and I will put in one of those bright green visible beam lasers. We'll be getting in a bunch at work soon (
www.laserdome.com), so I'll probably be able to get it for song... or at least a couple notes...
I also intend on wiring up a working trigger and game captured firing sounds to every one of my weapons...except the sword unfortunately...because there isn't enough room in the handle for a sound chip/speaker...
Link, I'd really love to see the spikers..