I would think that the amount of air flow required for 4000 watt lamps is not that much more than 3000 watts. Certainly, it requires more, but not that much. What size screen, throw? Do you really need 4000 watts, or is that over kill for your application? The screen needs to be lit with the proper light, but no more.

Check the manufacturers suggestions, and if you need to hire an HVAC company to redo the lamp exhaust system, make sure the required CFM air flow for every projector is specified in the contract.

Not having the rectifiers in the booth with the projectors can be annoying if you need to trouble-shoot problems, but I agree, it's nice not to have humming heat generators. 95F is a little warm; the 4000 IREM rectifers do not have a cooling fan in them; they rely on air convection only (don't know about the Strongs.) If you get the IREMs, can you rig up a fan to help circulate the air? How the fan would be rigged will take some thought, because the convection action must be created/maintained. You might want to wire up a remote switch (in the rectifer room) to turn them on for servicing/testing. For safety, I'd suggest indicator lamps both at the projector and in the rectifer room to alert personnel that power is applied. As for hum, we mounted large rollers under the rectifer. This reduces hum, and allows the back side to be serviced.