Acid, allow me to kpo a bit..
First of all, I must say that Ridz is truly an expert in this field with an unbiased opinion.
Secondly, I have to admit that I am a die hard supporter of the use of Inverter aircon.
U have mentioned that u may be using AC for all 3 bedrooms on warm nights. Since a warm night is going to affect all 3 rooms at the same time, I assume that all 3 will be on .. on the same night. That’s a 30K BTU effective load. Not many non inverter models can give u an effective 30K load at the same time. My Mitsubishi catalog says only the biggest MXY-4A38VA can support a cooling load of 2.5/2.5/3.5 at 1 time. Anything smaller, there is no guarantee of coolness. Even the huge Daikin 4MKS80DVM can only give 2.21/2.21/3.08.
Thus.. assuming u require 3 rooms cooled at the time, and there is space for only 1 outdoor unit, inverter models would be the only solution.
And if u are getting that 4A38VA model, might as well get the 4th indoor unit (26K BTU) for the living/dining. 1 outdoor unit serve the whole house. Of course.. the model I am proposing is also probably the most expensive model, using R410A gas. But then again, if the aircon ledge available can take more than 1 outdoor unit, then there may be other cheaper options.
Inverter also has this wonderful feature of a tight temp range, which to light sleepers, is enough a justification to select inverter models.