Paul,
Go for the Commander. I recently purchased my second, a newer version with the TiN(?) coating and dual ball detents. The lockup is excellent. Just make sure you handle it before you buy it, as QC can be an issue (although better than it used to be). You also want to make sure that your hand doesn't release the lock when gripping firmly (it probably won't).
The Synergy is a sweet knife, but I would hesitate simply because of the thumbstuds. Unless Speedtech has rectified the problem, the thumbstuds are smooth and will make hasty openings difficult without MUCH practice. I have heard that they are going to start adding texture to the studs if they haven't already, so this may be a moot point.
The Sebenza, ahhh... what can I say. My favorite knife. A large can be deployed fairly quickly with practice. I would love to recommend this knife, as everyone should own one, but I believe the Commander is better suited for your intended purpose. As for scratches, who cares (on a plain version)? It gives the knife character and personality. CRK will make it new again for 20 bucks-hard to beat. Just make sure to keep the tissue around the knife, especially a decorated one, as the Allen wrench will put a hurtin' on the handle (Senator, don't say a word).
The SOCOM. Cute knife. I have owned 5. I don't have any now. Nuff said. If you want to display it or collect it, great, but I ain't stakin' my a$$ (or fingers) on it.
Funny you haven't mentioned the Military. I have seen Sal open one faster than most people could THINK about opening a Commander. It is a stout and VERY well made knife. I trust mine as much as my Sebenza, and thats a bunch. At the prices these are going for, I think it would be an excellent knife for your uses.
Just my opinions from 10 years of experience with tactical (ugh) sharp things.
Later,
Chris