I am not sure if the slide windows come in dual pane which may be another consideration.
I believe the pop-out windows (called jalousie windows) were introduced on PCs some time around 2011. Our 2007 PC-2350 has sliding windows and we paid more for the thermal pane option. They are made by HEHR.
I imagine the best place to get your answer regarding interchanging of windows from jalousie to sliding, is to call Phoenix. You might also find your answer on the HEHR website but the link to get there does not work for me at the moment.
If the two different windows are interchangeable, it does not seem difficult to do...at least not installing the sliding windows.
