You don't need SnD in there at all.
With even a one point Eviscerate (or Envenom), it places a five point SnD on the target.

You might want the first castsequence as something like this:
1st) /castsequence reset=combat Mutilate, Eviscerate, Null



I've not seen a decent rogue click macro...
There have been a few castsequences on the boards.

I'm sure quite a few will be interested in whatever you come up with.