Why would you post that here? This is the Mysteries of the Sith board FFS, post KOTOR questions on the KOTOR boards genius.
and for Gods sake don't triple post, you could have just edited the original one.
Heres what should happen:
Bao-Dur should offer to help you build a lightsaber when you have the parts,
from then, when you talk to him, ask him about the lightsaber and he will tell you what parts you are missing.
When you have all the parts, ask him about building a lightsaber and he will ask you what colour you want it and whether you want a double or single-bladed saber.