Not sure exactly what to call these, but the Dynamix HWS range that come with the 'installation accessories' normally have 4 of those plastic push-pin standoffs that mount in the 'comprehensive hole matrix', which is all great, but 4 is never enough, and I've never been able to locate these to buy on their own. 

Has anyone located somewhere to buy these on their own, or an equivalent product that works with the holes in the HWS range?