No real easy way about it. Each vivarium will need its own thermostat (especially if using ceramics or lamps), so that's 4 plugs. For lighting, if the reptile need UV, then that's another four plugs. You might be able to cut the plugs off the lights and wire them together into a distribution box (best see an electrician) to cut down on some plugs.
But basically there is no real easy way to reduce the wiring.