Alright i'll help you out. I'm not sure exactly where it is but it's called the Crystal Caves, trust me it's worth it. Unlimited Lightsaber Crystals. You get two more lightsaber from the Mandalorian Leader once you kill him, but watch out he uses dual vibroblades that are fully upgraded and they pack a punch. Once you kill him search his remains and you'll find two lightsabers one red blade and one blue blade. If you use the red blade you'll get some major dark side points added to your character.
I hope this helps you. JediJosh80