Agents are tied to the Empire, same as Bounty Hunters, just a fact of gameplay. With that in mind, Agent is definitely closest. Rogues are famous for stealth, which Bounty Hunters can't, and not for jetpacks, which BHs can. :P
"Sir,we are beginning our search for these rumored 'underwater villages'.They will not stay hidden for long". -Battle Droid Commander OOM-9!