Nicholas Dodd, who's been orchestrating for David Arnold since StarGate, now has two scores out: Renaissance, which has much of the texture of the more magical moments from StarGate and ID4, and bombastic swashbuckler Treasured Island.
William Ross has spent most of his career as an orchestrator and has been moving into the composer game.
It's fairly standard to start as an orchestrator and, if you've got the chops, make your way onto the field.
> This kind of came up with The Legend of Zorro as well, but you can google
> the names like J.A.C. Redford and Carl Johnson to find their websites and
> listen to their own music, which most of the time is pretty good stuff.
> While I'm sure Horner writes all the themes (his style is a bit obvious)
> and hires orchestrators to save time (who doesn't) I sometimes have to
> believe they're doing a tad more than just "arranging" and thus
> wonder why these guys aren't getting more high profile gigs. They're
> obviously capable enough. I find it surprising there aren't as many Don
> Davises as there are Zimmer clones.