Perhaps the speed is not an issue here...
Maybe all they need in SW universe is accelration.
In our galaxy, there is some very thin shitty gas between huge distances. So thin that it doesn't really affect anything but a very fast moving ship. Those molecules are likely to damage ship when they crash in it at the speed of light.
But if the SW universe is free of this gas thingy, then all they need is a ship wth enough thrust to rise the constantly and steadily.
2 km/h
4 km/h
16 km/h
256 km/h
65536 km/h
So the amount of fuel is the only limit to their speed. As there is no friction is SW Space and apparently stuff can move faster than light. So longer they burn the engines, the faster the ship goes. Another story is to find out how they decrease their speed.