You want all your GEAR on the same phase, because any grounding problems will limit fault voltages to 120 volts instead of 240 volts. This makes a mistake much less deadly.
You should put lights, HVAC, etc, on the OTHER phase to balance out the load - keep in mind, though, that it's likely your studio stuff won't be as much of a load as everything else, so if you need to put any NON-electronics stuff on a phase with the electronics, I recommend doing so with LIGHTING, not HVAC or plugs where a refrigerator will be connected.
That way, any spikes caused by turn-on and turn-off of heat or frig's will be on the opposite phase from the electronics.
This last part just makes it less likely you'll have interference in your electronic gear, it's not safety related... Steve