Of course you know the first thing I am going to recommend is use a steadicam and get rid of the dolly. 🙂
Otherwise (w/dolly or steadicam) I would recommend the ring light around the lens. We sometimes will strip kino flo lights to bare bulb and walk right next to the operator holding them (5600K) since they are cool to the touch and use them as fill.
If it wont be obvious you can pull the fake ceiling tiles and place angled (towards talent, away from camera) soft lights (rifas w/X65 bulbs or kino’s).
The boom op can reach over the steadicam operator. (did I say you should use a steadicam?).
If you use the dolly you could additionally mount a sunbouce reflector and put a 500w for softfill?
The problem is if your key is too close and the hallway is not lit too well is dealing with the dark tunnel look. Your diagram gives the impression you might not be able to have too much separation.
Can you post some pictures of the location?
Emre Tufekci
http://www.productionpit.com