I've just noticed the listing you give of your favourite groups (which is similar to my own ).
And so I felt obliged to let you know of a glorious Belgian band known as " EFTERKLANG " (which I'm told means 'Afterglow' in English).
If you love SIGUR ROS then I must advise you to try out " Tripper - by Efterklang " which to my ears is just as transporting and a gentle sound all it's own, with both classical strings, woven through with subtle Electronic sound-scapes, and a male and female singer both singing perfectly understated - in English (there are even areas of choir-boy melancholy lifted by hope in the purity of the voice). They've done a few albums now, but tripper was the one that pinned me to my chair!! A perfect place to start !
you obviously have good ears so I really can only ask that you take a listen - Something truly not disappointing!!
Good luck and Good Health to you - Zetetick