Part #1 - Ithorian on Telos - after you help him with a couple of problems, he
gives you a part.
Salvager on Dantooine - The guy you rescue 1000 credits gets it from him
(not sure about this one but he does sell you a lightsaber part in the trade off)
Plus, one of the Female Salvagers is a trader and you can buy your Robe and
Crystals from her, as well as entering the Crystal cave for more crystals.
Dead salvager Will on Dantooine - get the part from turning in the salvager Will to the militia (you have to tamper with the Will, nets you dark side points if you do)
I have played the game 3 or 4 times now, and I always go to Dantooine after
Telos, so I can get my saber early in the game. Usually when I am about midway
done with Dantooine I have my saber. If your going to the dark side and plan on
killing the Jedi Masters, then you might want to rethink this. Varook is hard to kill
that early in the game.
Just a few suggestions and input, I may be wrong about some of it but thats
how I do it. Good luck