I'd back up skipping on a six-line... unless it is pretty much on it's own. The one I had constantly harassed my clowns and blenny for no other reason than to be a pain. Didn't matter whether it was hungry or not. It was friendly for months, then turned into a devil... and ultimately committed suicide on the carpet. Others warned me, and I thought I got lucky at first

Yeah, the tank was covered, but it found a way out. Others have had luck with them. Take my dwarf angel. Mine is a #$^$^and munches the heck out of soft corals. A lot of other people have a lot of luck with them.
If you go to a 40, or larger someday, a melanurus wrasse is worth considering.
I have the dwarf angel and a melanurus wrasse in a 40 breeder. The melanurus gets pretty big, but, as those are the only two fish that will be in that tank, they have plenty of room. Their other 'roomate' is a mantis shrimp. But, I went into it knowing I may have to move the wrasse out.
For an alternative, I'd suggest a Midas Blenny with the clowns. Awesome friendly/interactive fish. BUT, they perch and peek most of the day. Nothing like a wrasse which is a very active swimmer.