Hi Catherine. I suggest going for side by side blockout roller blinds in a white or other neutral colour. These will keep out the morning sun. Cover this with a sheer curtain that can be used the rest of the time. Sheers come in varying thicknesses, so you can choose how much light you prefer to let in.

although i always prefer curtains a 6m wide opening will need either a very light fabric or about 1 m either side to fully pull back to each side where blinds would be able to be raised completely above the window (assuming there's somewhere to attach them) discuss options with a window covering specialist as there are some new options that may suit you better..i also suggest to clarify flyscreening, security and ventilation options for your very wide opening as we found a more flexible and cost effective result with a door height panel of stacked awning windows next to a wide section of stacking doors so that we can open the window for ventilation without opening the doors

I agree that you need a blind like a roller or roman that goes up and out of kitty's way. Nobody has yet addressed your query about panel glides: Panel glides work best on large doors where there is room to stack the panels when opened. you will lose at least one third of your left glass door panel if you use panel glides and they also project into the room quite a bit.

What performance is more applicable for your climate? Double glazing will perform significantly better than single glazed whatever in regards to heat loss. You can't beat the air gap factor if you're trying to keep avoid heat loss. Yes there are "Low E" single glazed products such as viridian Comfort Plus which depending upon which side of the glass the absorption coating is placed it will perform in different ways, but bear in mind that since it also will reduce heat gain in winter it can actually work against passive solar building performance if not properly applied. In other words, it's not a "cheap" replacement for double glazing. In Victoria, we generally spec standard double glazing and use external controls such as blinds to mitigate heat gain issues in summer. Thermal Performance Specialists such as an Energy Raters understand the technical nitty gritty around this issue the best, and always good to seek their expert advice when applicable.