Well, my first game of Kotor2 I was so stupid as to do Nar Shaddaa last... and *gasp* no HK. I checked EVERY other game after the first what HK parts the sellers got and they always got the same as the previous game, and the one before that, and the one before than, and the one before that etc.
HK parts; Peragus (another copy can be bought), Telos (another copy can be bought), Nar Shaddaa seller (unique), Wharehouse (unique)
Visas: Cutscene needed (75% alignment toward LS/DS). 2nd/3rd lightsaber part NOT needed...
And something is absolutely wrong with that?