Balance of Force 1

[Mitchell]

Hmmm true. He was nine hundred when he died. I wonder how that age extension would work for Ranma who has both a significant Ki-reserve and is very strong in the force (at least in female form).

[Pale Wolf]

And consdiering at LEAST one Xwing desgin uses Tibanna gas...

On the E-Wing, they required spin-sealed Tibanna gas in their lasers, if I remember correctly...
Alright, checked my reference: 'Initial battles showed that the laser cannons were underpowered because they used synthetically spin-coiled Tibanna gas'.
That's the only fighter I can think of that mentions the use of the gas, and it's still in the weaponry.
Just in interests of correctness - nobody but us oldtime Star Wars nerds will even notice, but if you don't want to stretch SOD, you could just jumble together a few random syllables to make up a new chemical that she needs.

[Waruiko]

you could also go the route of useing a fule sorce from another story/movie/manga/anime... I would go with Veria or something similer myself, heck if you realy need something to put on that list just use anti-matter. less than a gram would do it, and it's hard enough to make that it could be one of the things on the list that can't be obtained.

[bissek]

Waruiko, in the books they stated that Luke never did find out was Yoda's species WAS, let alone how long they normally live.
However, Jorus Cbaoth was born 112 years before the Empire was formed. His clone, Joruus, was brought to an age identical to what the original was when it was made. The clone died five years after Endor, which happened maybe 25 years after the formation of the Empire, making Joruus roughly 140 when Mara killed him (The current confirmed record for oldest human life span is 135). And while Joruus looked old, he was hardly decrepit. So Jedi life extenstion seems probable. Why the Jedi didn't notice that Palpatine was using it (He was on the Senate eighty years before he became Emperor - Cbaoth was his personal Jedi advisor in 77 P.E.), I don't know.
I don't think antimatter is ever mentioned in the SW universe at all. Fusion reactors are used, however, and since nobody's sure what needs to be used to create stable fusion reactions, the chemicals needed can be made up at will.

[Nekomata-sensei]

Why the Jedi didn't notice that Palpatine was using it (He was on the Senate eighty years before he became Emperor - Cbaoth was his personal Jedi advisor in 77 P.E.), I don't know.

At that point Republic medical technology seemed damn good. That might be the reason for how long they live, not jedi arts.

[ranger5]

The longevity factor could be a combination of the two. The force/ki AND medical tech. Working together would make a long life with excellent health not only possible ... but probable.
Heck just the improvements in medicine we've made on earth in the last two hundred years has had a major impact in longevity.