The 2 clamps you reference work differently. The Veritas uses the threaded shaft (via a bending moment) to connect the clamping force to the workbench while the plastic one requires that the back end of the clamping bar is supported. This support connects the clamping force to the table (threaded shaft is only in tension - no bending). This feature (of the plastic one) is what permits using the weaker plastic material in the shaft (i.e. only tension - no bending).
In addition, the Veritas clamp can be used from just the top side of the table (very handy) while the plastic one will require attaching the nut to the shaft under the table (can be cumbersome). Also, the Veritas will provide a greater height reach.
Since the Veritas is like an adjustable dog hole clamp, you could just use a dog hole clamp like this one: dog hole clamp
if you have a suitable workbench (you would need a sufficiently deep hole for it to work right). These are very quick to lock and release (tap with a mallet) but might be prone to damaging the workpiece unless an intermediate protective piece of wood (or something) is placed under the clamp pad.