Feature Fish Suggestions!

[Bowen]

Hey! I'm still setting up my (first marine, not first overall, and I work with baby salmonids) tank and I'm trying to hammer down my stocking list. I've settled on a pair of black clowns, which should be going in in a couple of weeks, and a small (3, 5 at most) group of one of the black and white chromis species (recommendations between margaritifer, iomelas, hanui, and the rest are welcome, especially since they seem to be misidentified as each other quite often).

What I need to pick now is a feature fish of some kind. I'm looking for something fairly active and relatively large (4-5 inches, no average adult sizes over 6"). Colours can be dark (but not overall muddy/bland) or vivid, and the particular colours I'm not picky about. I'm very open to carnivores but they have to be too small (at least in the mouth) to go after clowns and chromis; it might be a year or more before I get this guy, who will undoubtedly be the last major addition, so everyone else should be close to full grown. The tank will eventually be planted with macroalgae as well, so herbivores are welcome. The single defining characteristic I know so far is personality! I'm looking for an interactive, curious fish that won't devour absolutely every soft coral I have (which isn't much now, and I'm not planning a coral-dominated tank).

Tank specs! 48" by 12" 45 gallon (which is long enough to make me eye the little bristletooth tangs like the whitetail, but it isn't fair to anything to be more than half the smallest dimension of their home) with a 30 gallon sump that's probably closer to 20-25 g in water volume. The majority of the sump is refugium with a 3-4" sand bed and will by heavily planted with macroalgae once I find a store that doesn't sell useless slime. I have about 40 lbs of live rock in total, and an inch of now mostly live sand in the DT. I also have a large (5+ gallon) trickle filter that will be plumbed by the time the big fish arrives, as well as a very large biowheel filter running straight fibre and activated carbon (not sure of the specs for either, since I got them both free), and a remora skimmer that doesn't do much and I'm thinking I'll have to replace.

I've been digging around a bit, and so far the best ideas I've come up with are a whitetail bristlenose tang (max about 6", average captive size probably closer to 5", not that hard to take care of but very hard to find and probably mixed with juvenile koles a lot) or a longnose hawkfish. I'm not a fan of wrasses or anything else that jumpy. Mandarins interest me as well (remember, lots of time before this fish goes in), but they're a bit on the small side for me.

So. Any thoughts? I'm willing to wait and I'm willing to pay a fair bit for the right fish - but only the right fish :P