I like the sniper/
ML option, because it allows you to hold an objective while letting your tougher, harder to kill units move forwards to claim other objectives. For 100 points you have a unit with 3+ cover saves with the ability to deal with big nasties at range.
Well...that's codex anyways. I prefer my
SW scouts. In that case, I take a melta and a plasma pistol or two (I know they're expensive, but I like them

). They pop up in your backfield and wreck a tank, forcing you to deal with them lest they take out another. I would NEVER take wolf scouts with sniper rifles.