The lightsabers you can build at trading post I think are the kids plastic ones, for sure not the Savi parts. I think droids are the same way, you build action figure sized droids, not the remote controlled ones from Droid Depot - though Trading Post does have fully assembled remote droids I think. Maybe they added some Droid Depot parts to Trading Post, but I can't remember seeing much of that there when we went a month or so ago.
I believe you can buy some of the legacy sabers at Disney Springs, not sure if they have the full selection. But you could at least take a look at what they have there and they should let you hold them and try turning them on to see what you think.