Efficient air condition (water cooled?) units, vendors and installers

Anybody have recommendations for good quality air conditioning units that are very energy efficient?
I am considering water cooled A/C. Seems like an obvious choice because the air is so warm and ground water is so cool. Anybody have experience with that?
Usually water cooled units are used more in commercial applications.
Anybody have A/C vendors or installers to recommend?
Thanks, in advance

No recommendations?
Anybody know how to size AC units optimally for this climate? i.e. How many BTU's per square meter of living space?
Any recommendations based on long term experience between Mabe, Midea, Samsung, Prime AC equipment?
I have been recommended Samsung & Prime.