Alternative bracket for wardrobe organiser - suggestions please.

Just installed a wardrobe organiser which came with these brackets:

Because they doesn't clamp around the hanger bar, a load any distance away from a vertical strut tends to pull the bar downwards:

I think what would be better is something like these which I found by searching for "cable clamps":

Unfortunately these are on German or US websites and, I suspect, in some cases only available in quantities of 1000.

Can anyone suggest a source of something suitable or an alternative?

Thanks in advance.