Try to go with inverter AC's as they have the latest technology and save quite a lot of power. Mitsubishi is the best among the brands available in the market.
Use this online tool to find the tonnage of ac for your room. Find My AC
All AC companies have a tonnage calculator which take into consideration additional factors like which city, floor you are on, glass exposure, location of the room (East, North West etc) and finally no. of people. Based on those parameters you will get a recommendation.
My recommendation for your room would be 2T - the additional tonnage will give you some headroom.