Depends on the place u r using .

Inverter concept in a simplified version :

Inverter Compressor can work from 10 % of Cooling load to 100 % load . At 100 % cooling load, the power requirement is slightly higher than a non inverter version . The savings occur when , your cooling load is not as high allowing the unit to run at part load . This is the moment where energy savings occur .

Non inverter concept :

Non inverter compressor runs at 2 points . O% load and 100 % load . When u switch on , compressor will run at 100 % . When desired room condition is meet , compressor will continuesly run until room temperature continue to drop ( maybe thermostat detects , room below 18 deg c ) , where it will cut off compressor and wait the room to hit 25 deg C before starting to run the compressor back .

So , if you wish to know where is suitable to use inverter : 

Your bedrooms : USE INVERTER . Unless u r undersizing the ur DX Split . if ur room height is standard 2 m tall with all windows covered by curtains , you may apply 55 btu/hr per sqft .
Living room :

Use non inverter. Most houses usually undersize the living room dx split . It's meant for spot cooling . Even when u use inverter compressor , the savings doesnt take place cos your unit will end up running at 100 % anyway .

I hope this clarifies your request and kindly feel free to contact me if you need further explanation .

in terms of brand to go for :

Hands down to mitsubishi electric and hitachi . Dont fall for Daikin / Heavy industry / Midea / Gree / Trane / Panasonic / Haier / Jalan Pasar split .