Think it's all been said already, but I feel the need to reiterate that Lightsabers in general, and crystals specifically, don't really need any additional benefits (although there's aways room for more types of lightsaber crystal!). The rules put forward are a nice compromise between fairness and power, with heaps of options for customisation and personalisation, at least as far as I'm concerned. If you want to give some special additional award for a moment as epic and iconic as a hero forging their first Lightsaber, I would recommend a useful but temporary benefit like a few boost dice from heroic inspiration, hands-on guidance, or ancient manuals to start them on what will probably be a campaign-spanning journey of upgrading, modifying and perfecting their signature weapon.
I also strongly caution *against* destroying or otherwise permanently confiscating precious items like lightsabers, holocrons or even the trusty blaster they started the game with if it's valuable to them without a really good, story-driven reason to do so. A hero's weapon, be it a Jedi's Lightsaber or a Scoundrel's signature blaster, is as integral and as iconic to a character as their style, their code and their deeds. Hell, the Jedi don't name their sabers because from their point of view, it would be like naming their hand, and naming your hand is just weird. If a saber has to go for the story to proceed, make the crystal and enough shards of the hilt recoverable to build a successor weapon, if your hero's signature DL-44 is confiscated or stolen, give them a chance to track it down, or have it show up in an unexpected place once they're back on their feet (Don't forget that the Seek power can turn a prized weapon into a homing beacon, a perfect opportunity for a dramatic scene, like duelling an Inquisitor armed with the hero's masterwork Lightsaber in order to wrest it back!). Taking precious things in the name of "realism" in a fantasy space opera is a @#$% move, returning a player's personal Excalibur when the time is right demonstrates that you appreciate its value and is an opportunity for roleplaying a scene as epic as the moment they first forged the weapon they just went through hell to reclaim.
I won't pretend that this is anything other than my opinion, but stealing/breaking/ruining your player's signature items out of expedience or entirely inapropriate and undramatic "realism", is just lazy and/or malicious GM'ing in my book.
Edited by Azraiel