Be aware that the optimal modding when DR has a pre-taunt tank with him (usually Sith Empire Trooper) might actually be to have Malak fastest with DR a hair slower than Malak, but still faster than the enemy's DR.
In this case you can dispel the pre-taunt with Malak, and then fear-lock the entire enemy squad rather than just fear-locking DR and his tank (or one of his tanks).
This has worked well for me and gotten me quite a number of holds on defense in GAC. That said, it is mod intensive, getting two toons faster than the enemy DR instead of just one. And it's particularly resource intensive in your GP bracket where for many people Darth Revan is literally the best toon that they have and is likely to get their fastest mods.
If you're perfectly on par with them and you are each using your fastest mod sets on DR then you have a 50% chance of having a faster Revan and 50% of having a slower one.
Getting your **second fastest** mod set faster than their fastest is much harder.
The good thing, however, is that this isn't a random chance. You can choose to spend more on mods than the players you are fighting. At your GP level, you want to sell every mod that has no speed present, and probably want to discard mods that don't immediately hit speed a second or third time.
While there's a lot more to mods than just speed, speed is going to be what gets it done in Darth Revan mirror matches. For that reason, I would strongly recommend that you spend as much as reasonably possible on Mod Energy refreshes and level up all the blues, purples and Golds you get to Level 12 so you can see which mods have +15 speed (long term keepers and mods you should upgrade to 6-dot when you have a chance) which have +10 speed (medium term keepers at least, and some of these will be long term keepers based on their stats other than speed), and which have +7 or less (definite sells).
For mods with +8 or +9 speed I recommend just letting them sit for a while as you get more experience with the game. Eventually you'll have a much better idea which low-speed mods are still worth keeping, but this depends on whether they are right-side or left side, on whether the set bonus matches the primary, and more. I wouldn't want to encourage you to make those decisions right now when there are so many other mods you could sell to make room for the ones you're letting hang around,