I wouldn't be too concerned about the cooling system itself but rather the quality of the insulating properties of your windows (glass), walls, floors and roof. Imagine setting a Yeti cooler and an Igloo cooler side-by-side outside under the hot sun for a few days. Both cooler brands are capable of holding ice just fine. Although, which brand will keep the ice from melting the longest? It comes down to the quality of the insulation and the seal itself, where cold air can escape and hot air can enter. Yes, the Yeti cooler will usually cost two to three times more than the Igloo brand. The same goes for your choice in windows. You will pay for more up front for the higher-end windows but you should save even more in the long run when it comes down to cooling costs. Just my opinion and no bias here. I own both a Yeti and Igloo and put them to work regularly. Congratulations on your new home!

Saludos,

Ernesto P.

In a house that large, why aren't you considering a traditional ducted split system?

Is natural gas available? If it is then you may have better options than ducted mini splits.