Why would that make it easier? Amps don't have a traditional "range"; they rely on the user's spacial awareness, which is why line of sight is recommended. The cameye-goggles should be more than enough. The more complicated your plan is, the less likely it is to succeed. Why risk setting off traps when none of you even have to go near the room? Why risk a confrontation when Lars can just knock them out with his amp? He could probably do them one at a time, with dynamic bonuses charged in-between, if it's handled right, too.
You could send the target into a separate room; make him feel tired and have a nap, maybe, and then have one of the guards feel an urgent need to use the washroom or something, and send them into temporary comas one at a time. Then pick the target's sleeping mind for info, maybe puppet him so he can dispose of any physical evidence himself, then selectively wipe his memory, so he doesn't even realize anything's wrong or different after the fact.
FAKEDIT: Ninja'd, kinda.
Amps (and manips)
do have range, of sorts. The further away one is doing stuff, the harder it is to do. I believe it's the same for automanips, so it's probably more than simply the user's spacial awareness that makes it hard.
That said, I highly doubt being a floor below the guy will have much of an effect compared to being next to him. As far as wanting him unconscious, wait until night first, and do it while he's sleeping. Easier than literally busting in and choking him unconscious or whatever.
My recommended plan would be to wait until the guy is asleep, have Lars wear the goggles and memorize his exact position (roll will until you get a five), then hand the goggles to Thomas, and have him and Milno go upstairs to the room directly opposite the target's. Lars tries mind control, and if he F's up, he radios that pair and thomas shoots the guards through the door with his carbine. Then you breach how you want, and just go with whatever your plan already is.
If you want to kill them in silence, have Skylar use his micro manip to roast them, while wearing the goggles,
then breach.
In other news, I think Anton will feel a bit left out once our robosod forces on Heph are a bit more complete. Message Saint over the radio, and suddenly Saint possesses his sod bodyguard and just starts talking. Especially if Simus and Charles take advantage of it too.