Honestly the best names are the ones you aren't quite sure how to say. It keeps people talking about it too.
Of course you can always go simple, That Guy Kevin.
Or you can do the first letter flip thing. I.E. Mord Fustang, Com Truise, ect.
I myself just go by Gabe D. I don't think anyone is using Kevin S so that may be an option. Although there is nothing wrong with Kevin Seguin.