I have 4 trochus in there, 3 green speckled turbo and 1 Mexican turbo. They are keeping everything but the sand pretty much spotless. Think I’m gonna work on manually siphoning it out during water changes.For wrasses, you could also consider the Pink Streak or the Possum. They are a bit more shy than a 6line, but awesome fish and very friendly.
For the GHA, perhaps a tux or halloween urchin. I've never seen rock cleaner than where my Hallowe'en Urchin has recently passed. Even the longer strands. Trochus snails are also excellent, as are Margaritas.
I would like an urchin, my only concern is my rockwork is not epoxied together.