I agree with what panty said. If you are just starting out, then yeah, don't worry about it until you're ready to give out mixes, at least. Even if you're not comfortable enough to do nights out, but ready to makes mixes to record and pass out, you'll need something for people to identify you by if they're into it. I myself went thru a few names before ending up with what I use..and that was after I started posting my tracks, so never too late to change it if you don't feel it after a bit. But yeah man, as panty said as well, make it something that relates to you, not just some made up name to throw onto a CD or flyer, etc. Although I'm not a detective by trade, it does have something to do with my name,.
Also, I know what you mean about other people already using it, that's why if ya come up with something, do what i did and google it, see what comes up. And if you have to then yeah, change up the spellin' a bit, etc.. pz & respect to ya' and good luck with it.