I actually think both of these combatants have been made out to be gods. To most, Revan seems invincible. To others, so does Luke. This is where the creators of the KOTOR games and NJO books went wrong. Luke and Revan are basically two gods and apparently no one can compare.
This, my friends, is where Star Wars goes completely wrong.
And since both are practically immortal through their god-like powers - I don't know WHO would win.
Both are some of the strongest Jedi/Sith the Galaxy has ever seen. People say Revan is one of the strongest sith but I'd say that Luke was one of the strongest Jedi. It's like Ra vs Zeus. Battle of the Gods as Darth Somebody said but the one important fact is that the first person to make even the slightest mistake is dead.
They're both Gods of their respective sides both seemingly invincible leaving it down to who will make the first mistake, I personnally think that lukes skywalker idiot gene will kick in eventually and he might make a little mistake, especially considering revan has his pre-cog ability and he's probably the most levelheaded cunning tactician the galaxy has ever seen as well as the fact that he excels at killing/turning jedi so he could probably eventually get luke angry enough to stop using his head and use his emotions which coupled with his pre-cog gives him a chance of creating and exploiting a mistake luke would make, I sort of brake it down like this
Intelligence:Revan
Planning/tactics:revan
calmness:Revan
knowledge of combat:Revan
force potential:luke
raw force power:luke
force knowledge:Revan a couple planets worth of info compared to a single library...
lightsaber knowledge:Revan
lightsaber practice:Revan
will:Revan
Lightsaber technique:hard to say revan has awesome awesome technique, but NJO luke is a decent swordsman not that anyone he's fought has been that great in terms of being a melee combatant, NJO's pretty damn good with a saber chances are, but so is Revan, lets just say equal.
Unique bonuses:Revan has battle pre-cog and insanely powerful force attacks some of which simply can't be blocked
Luke has insanely awesome force powers that are powerful on a large scale, however I doubt they'll be of much help in a one on one duel.
Overall:Revan but barely barely barely as even with the catagories he wins he wins them barely except for the intelligence ones which he wins by an ok margin.