DuracellEnergizer said:

Well, in the later TOTJ comics, it was established that around 5000 BBY, the Jedi wielded archaic lightsabers with external power packs while the Sith didn't wield any lightsabers at all. That all got retconned later, though (I'm not sure where), and now the Jedi are depicted as wielding archaic lightsabers as long ago as 7000 BBY, with the first Sith Lords even depicted as wielding modern lightsabers.

I don't see how archaic sabers in 5000 BBY = no sabers at all in 7000 BBY, but the first Sith Lords having modern sabers is absolutely wrong. The first Sith Lords lived before the events of the comics with the archaic sabers.

Interestingly, the idea that the first Sith Lords had lightsabers at all originated with Kreia saying in KOTOR II that Tulak Hord was among the first Sith Lords and was an excellent lightsaber wielder. Possibly to accomodate that, the first Sith Lords were retconned to have lived in 7000 BBY instead of 25,000 BBY as previously implied.