Maple, Rosewood, ebony fretboards for metal.
The density of the wood effects tone.
Maple produces a warmer tone, and gets brighter in rosewood, then ebony being the brightest (which is a very dense wood). The denser fretbaord usually means more sustain. All of this can be effected by body wood though. Alder and basswood are brighter. It's hard to find ebony on low to mid-priced guitars. Ebony is harder to work with and more expensive for the manufacturer, therefore they opt for rosewood. For refret jobs, make sure you have a tech who knows his stuff otherwise ebony will "tear out" and you end up with a junk fretboard.

When you replace the stock "licensed" tremelo with a real Floyd, you will notice the real Floyd is much, much brighter. This is because the licensed versions are cheap "cast" parts and the Floyd is hardened steel.
(Caution - Changing the trem may mean plugging and redrilling the stud/post holes due to differences in stud/post width measurments). The Schaler licensed trems are very close in dimension to the real Floyd's. In most cases though, NONE of the parts from your licensed trem will match up to the Floyd's but it is well worth the money and effort to put the real thing in place.