When I got my D-max last year, I ordered the isuzu (ARB) canopy with it, as it was by far the best deal. It is actually an ARB canopy, complete with ARB badges. Also meant It is covered by the 3 yr warrnty with the vehicle. (see pic below)
In terms of how it was chosen in terms of hi roof/same height as car roof, windows etc it purely depends on your intended use. There is really no right or wrong style.
For me, I wanted the finish of the canopy to be smooth to match the car - looks better & easier to clean than the dimpled finish IMO.
Next, lift up side windows a must for access, and I don't know how I would manage with sliders.
You can still have lift up windows both sides with a dog as the front window of the canopy slides open and can be left open whilst travelling.
Next, I need the canopy to be flush height with the roof of the dmax, as we also have canoes that go on the roof bars, so a hi roof canopy wouldn't work.
There's more than enough space the std height canopy (still more than a wagon) so no dramas there.
Nutto