Spectrally Selective Coatings For Windows

I am planning to get tinted windows for my new house but understand the greater the heat reflection and tinting the less light passes through.

I do not wish to have a large number of windows as they are a weak point at keeping heat out. However I do not want a dark house.

I have heard of Spectrally selective coatings for windows which block more heat heat but allow higher levels of light through compared to normal tinted window options

1) Does anybody have any knowledge on this types of tinting, its availability in Thailand and the extra cost load over non tinted windows.

I have been told metallised tinted windows may add around 10% but I am now think that level of tinting may block out too much light.

I may need to compromise with a lighter tint. Does anybody have any idea on a good compromise ratio and what that might be.

Regards

Dave