Weather News; Calif. fire leaves behind 'moonscape' as it threatens more communities Los Angeles Times; Storms may mean White Christmas, travel headaches AccuWeather; Northeast cities face brutal week of bitter cold, snow AccuWeather
You can either go for a 1 ton AC or a 1.5 ton AC depending upon the amount of light that enters the room, area and direction of windows, the floor on which your room is situated, number of people occupying the room and the number of lights.
A typical 5 ton AC with an EER of 12 will use about 5KWHr per hour of use. At 240VAC, that would be an average draw of a bit more than 20 Amps. The peak draw would be somewhat higher than that and would vary quite a bit with age, condition, and quality of the equipment. It is most likely equipped with 40 A, 50 A or even 60A breakers.