Can't add anything to what's been said...except that there are currently two Mods in the works, to recreate both Dark Forces and Jedi Knight in the new Jedi Academy engine. You can find more info in the Dark Forces MOD forum
. Hopefully these mods will be completed (there are a lot of dedicated, and talented people working on them), so you should be able to play the recreated games under Jedi Academy.
Oh...and Jedi Academy features old Kyle Katarn as well, though you don't get to play as the character.