I did a campaign based before the Clone Wars broke out (but expanded with d20 modern cybernetics rules, ftw!). The Emperor was confronted by Qui Gon, everyone died. Life continues
My immediate questions:
1) how many sessions? (not ever, I mean for a specific "arc") This will give you an idea of what you want to cover. For one arc you may want to follow the 3 planets rule, or something. Many encounters, 3 strange locations. Also the kinds of different "events" you can do at each one. The rest will be backdrop, basically, with a pre-yavin story; the difference is the Death Star, and no cavalry army at all.
2) What are the aims you want to throw at the PCs? Like, are they trying to build an army? They could use Droid manufacturers or even Cloners from Cameno. Heck, they could also go after the Katana fleet, or some other missing fleet of ships they download. Bam, army and fleet. Done. Find another location, either to get the information from, or the final battle at, and you've got the arc. Off-hand: smuggler's den on Coruscant; Droid factory on Bespin (or a similar gas giant); Katana fleet on, er, Hoth (celebrities are fun, leave me alone

)
3) How "Force-Sensitive" are you aiming for? Is the Emp dead? Is Darth Vader around? Is Yoda an option? Sidious is sort of "evil Yoda". No one expects him to die of natural causes. He's the evil wizard, the necromancer; the lich! If he's the showdown in a Force campaign, that's one thing.
If you're ignoring the Force, then maybe he's really just a dude. Like Tarkin.
So here you'd want to pull a Skywalker: PC discover's he's a force-user; crash-land on Degoba, learn the ways of the Force and become a Jedi like Luke's father before him; fight the BBEG.
One section of one arc could be this. Or it could be getting into an ancient Jedi/Sith temple that's being used as a smuggling operation, and steal the plans to a weapon that could neutralize a Death Star with one shot. Or both.
The question is who the major FU villain/challenge for any section of the campaign is going to be. Or the melee/kung fu villain.
4) Finally: take a Japanese classic, like 7 Samurai, and make it Star Wars. Lucas did it with (I think) "the Hidden Fortress", right? Well, that's your session, with "the empire won" as the backdrop.