Alu-clad windows

I'm just building a house at the moment and am finding it difficult to decide what windows to install. I had originally decided on Marvin sliding sash windows. I looked at some German alu-clad windows which had a much better u value than marvin windows. These windows open in rather than out. I don't know how this works with blinds if the windows are inward opening. Has anyone installed these windows ? Any generl advice on windows would be appreciated???
Thanks

Hi Billy,

Running the search option in this forum for alu-clad gives

You will plenty of other info on windows using the search option in this forum only.