Air conditioner provide 2 functions. Reduce temperature and reduce humidity.
As far a comfort level is concerned the latter is far more important. It is a common mistake to think more cooling capacity is a good choice. It is not. You will be far more comfortable at a warmer temperature with low humidity than than a cooler temperature, with the unit short cycling against the thermostat, and higher humidity. A single properly sized AC unit will give you better all around results.
Now as for privacy while having guests you may have to seek cooperation among those staying with you. If a ducted AC unit is available that may solve your problem.
WBCCI 12156 AIR 3144 WACHUNG TAC NJ6
2004 Excursion 4x4
1991 34 ft. Excella +220,000 miles, new laminated flooring, new upholstery, new 3200 lbs axles