I saw you said you have gravel in your tank , Many inverts along with some fish like to bury themselves , my concern with that is gravel is sharp and can cut up the fish ,
inverts like to burrow through the sub straight gravel will make that difficult ,
Gobies also like to burrow ,
Wrasses don't burrow but they like diving into the sand if they feel threatened ,
they also bury themselves when resting .
Another concern is there are some bottom dweller fish that don't have scales like most other fish , this would be a concern.
before you start buying your stock be sure to research their habits , Example : do they burrow , are they bottom dwellers , do they dive into the sand , do they bury themselves , a lot of fish will also flash off the sub straight ect..
these are all big concerns with gravel , I would be concerned for fish getting cut up , this can scare them destroying their beauty ,
some saltwater fish are considered delicate . I think they all should be considered delicate , I always use the term fragile when talking about fish , this term sinks in because it is seen a lot on packaging ect , people also tend react to that word more .
so in closing please look into the habits of the stock your interested in a long with compatibility and also what size tank is required for that certain fish,
if your looking for a sub straight that really brings out the colors in your tank even fish
I would go with a black sand .
Fish are like chocolates you can't have just one!