1) The PC of KOTOR is not Revan, but another individual sharing the same body. Revan is neither a strictly LS or DS individual.
2) While we do indeed know the extent of what sort of level Revan is on, I admit we do not have a specific list of powers he may have held. Also, the knowledge of the Ancient Sith is fairly unknown. We are talking about an Order descended from a group of Dark Jedi who explored and mastered the art of manipulating life on the fundamental level who interbred with a highly-force sensitive race. The sort of teachings that Exar Kun's lot discovered was likely a mere scratch on the surface of what later spawned the almost-unstoppable Sith Assassins of Malachor.
3) Simulations always have innate limitations. Terrain is always an important fact in combat. While I think JKA has a great engine, I think that the engine and effects of TFU would be much more suitable for such a simulation (even though my opinion of the plot is low). Even then, there would be limits. What will be the pre-fight conditions? Such things have an impact as well.
I do think it's an interesting idea, I just don't see how it would work.
As of 3/14/10, TSL is restored. The Sith Lords Restored Content Modification by Stoney and Zbyl has been finished and can be downloaded here